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Halo 5 Mythic (LASO) Walkthrough by MythicTyrant

Home | Halo 5 Mythic: Days Gone By | Skullpocalypse | Keep Your Friends Close
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Osiris | Blue Team | Glassed | Unconfirmed
Evacuation | Reunion | Swords of Sanghelios | Enemy Lines
Battle of Sunaion | Genesis | The Breaking | Guardians
Halo 5 :Guardians LASO Challenge

Halo 5 Mythic Difficulty Guide - MISSION 12: Battle of Sunaion

The Tru7h About Battle of Sunaion

Rating: Hard

Type: Covenant-Heavy

If you're feeling at all guilty about just how easy the last mission was, the game is about to hit you back in a very heavy and brutal way. For me it's still hard to say which mission is more challenging, whether it be Blue Team or Battle of Sunaion as both missions are VERY long with tons of enemies and lots of easy ways to die. While it's true that there are several skips that can be performed in this mission, some of them take time to learn while others have a lot of risk associated with them. That's right. The base gameplay is so insane here that I'm actually recommending you do a skip that might not pay off. To top it all off, the Prometheans return at the very end of the mission under the command of the Warden Eternal. So on top of everything else, there's also a boss fight you'll need to worry about. And this time, he brought with him a LOT of friends...

Fall of the Covenant

To be totally honest, there's so many tricks and strict methods in this mission you have to perform simply to get from Point A to Point B, this written walkthrough can only cover the basics, meaning you're really going to need to watch the video in full to really understand what to do in order to do it well. The video displays everything far better than I could every explain it on paper. That said...

The mission starts out with a literal BANG as you're dropped straight into the heart of the Covenant vs Swords of Sanghelios war zone. Both the city and skies are set ablaze, and a small army of Grunts and Jackals currently stands between here and your first objective. That objective? You'll need to destroy six anti-air guns. Or at least that's what the game would have you believe. Instead, we're going to skip the first two entirely and only deal with the final four cannons. While the video does a better job of showcasing exactly what you'll need to do to pull this off, I'll give you the basic objectives here.

  1. You'll need to clear a path to the small tower on the right side of the area and use Sprint > Jump > Thrust to get to a small area in the wall in which you'll need to Ground Pound in order to pass through successfully. You'll then need to clear a safe path for yourself to the third AA gun via destroying two different soft barriers. This will allow you to bypass the enemies easier when you're coming back through. At the end of this trek, you're going to want to grab one of the Fuel Rod Cannons from the Covenant weapons cache.

  2. You'll need to head back to the starting area the normal way so you can load the rest of the mission. You won't be able to proceed until you do.

  3. Finally, you'll need to proceed through the mission normally. You can skip the second AA gun and use the passage you created in Step One to bypass all of the enemies until you reach the third AA gun. Use your Fuel Rod Cannon to destroy the gun so you can proceed.

It's worth noting here that it only takes three Fuel Rod Cannon to destroy one AA gun even on Mythic Difficulty. Once you've destroyed the third gun, you'll have to wait a moment for the door to open allowing you to get to the next area. I recommend taking cover in the meantime so you don't get bombarded by the Covenant Spirit as it flies past. The moment the door opens, a Fuel Rod Gun wielding Warrior Elite will charge through. Take this opportunity to make a mad dash past him while also leaping over the group of Grunts staggering behind. Make a quick left turn, head up the stairs, and make your way to the top floor of the closest tower. There are USUALLY three Grunts up here waiting for you. Pop them in the dome and catch your breath.

Time to get your barrings again. And you'll only have a moment to do so. There are three AA guns here. One directly in front of you, another further to the left being partially masked by another structure from your current position, and a third down and to the right on the bottom level. There are a LOT of enemies here, and you'll need to take out several of them (including the three AA guns) on your own before reinforcements arrive.

For now, focus on the neighboring tower to your left. Both Grunts and Jackals will boost up to the top level in an attempt to take shots at you. You can usually see the smoke from their jet packs before they even make the leap, and they typically come up only one at a time. There's usually a few Grunts followed by a pair of Storm Jackals. After they've been dealt with, you're relatively safe for the time being here in your little perch. Take out the both the center and left AA guns using your Fuel Rod Cannon. Next, send your allies down to destroy the third. Now you can use the rest of your Fuel Rod ammo on Shade Turret that's stationed right beside the center AA gun. You should also make note of the Plasma Cannon parked on the platform just to the left of the central AA gun as that can come in handy when dealing with the many Warrior Elites in this area.

What happens next tends to vary. Eventually, a Warrior along with a squad of Grunts will spawn in your tower, run down the stairs, and join the fight. What makes this group so dangerous is that unlike the other Covenant in the area, they can flank you by moving up and down the stairs freely, so bringing them down should now be your top priority. They typically spawn after you've killed 3-5 other Elites in the area. For this, I recommend picking up a Carbine from the ammo crate beside you (while using the infinite ammo crate to replenish), and start taking the Elites down one at a time using only the Carbine. Your first Elite should be manning the Plasma Cannon, making for an easy kill. If you're lucky, others will take his place. Don't send your allies to kill any others because you'll need them close by in case things go south when dealing the team that spawns in your tower.

After you've killed at least two Elites, start checking the top of the stairs. Do this with EVERY Elite that you kill after the second. When they do eventually spawn in, they'll be facing the stairs. As long as you're far enough back, they won't notice you, but as soon as you see them, run in and assassinate the Warrior. Use the Carbine to pick off the remaining Grunts, and trade your secondary weapon for a Needler. So at this point your main should be a Carbine, and your secondary should be a Needler.

Head back to the second floor and continue picking off the Covenant. Eventually, Mahkee will let you know she's on her way. This is your queue to jump to the second floor of the neighboring tower along with your allies. Two cloaked Special Ops Elites will spawn here, and you need to be quick about taking them down. Have your teammates run in ahead of you for the purpose of shielding as well as temporarily uncloaking them while they attack your team. From there, unload your Needler on them. It will take 2-3 super-combines to outright kill them. When they're finally dead, trade out your Needler for one of their Energy Swords, jump back to your tower to refill on Carbine ammo, and cautiously make your way to the elevator. There will still likely be other Covenant wandering around, and the Swords of Sanghelios will be actively engaging them once their Phantom arrives. Just make sure you don't get caught in the crossfire. Activate the lift once your allies are onboard, and head down into the depths of the under city.

This is where, once again, I'll have to refer you to the video. Your primary objective is to speedrun from one side of the under city to the other via platform jumping while using the Energy Sword for that ten percent speed buff. Fortunately it's a very reliable route that allows you to bypass the otherwise legions of enemies you'd have to fight. The only tough part here comes near the end while you're scaling one of the platforms as there will be an active Plasma Cannon directly behind you. Fortunately if you're fast enough, you'll be able to run around the bend well before its gunner even notices that you're there. Then you'll need to run up the path and through the door ahead, avoiding the shielded Jackals along the way. Once you're through, you're relatively safe. The Covenant won't chase you save for possibly a few Suicide Grunts which you'll be able to hear thanks to the loud hissing of their active Plasma Grenades. Take note of the extra Carbine ammo here, and trade out your Sword for a Plasma Pistol.

The next area is where things will start to slow down. You'll need to fight this one out in order to proceed safely. There are a series of platforms here, many of which are connected via a long walkway with a Plasma Turret manned by a Storm Elite at the very end of it. Directly in front of you, however, will be a trio of Grunts. Put them down and then focus on the Ranger Elite who's desperately trying to get away. Next, slowly peek your head around the corner and deal with the group of shielded Jackals waiting for you on the other side. Be careful though. On the bottom level of the platform next to them is yet another Grunt squad led by a ruthless Warrior Elite. Get your teammates involved in taking out the Elite while you deal with the Grunts. The platform further down houses another Warrior, so send your allies down there to flush him out.

It's here were I need to segue into your squad and their general behavior in this mission. They are absolutely clueless and reckless. If they're not constantly getting themselves killed or completely ignoring your commands, they'll occasionally even accidentally kill YOU! So you need to be very mindful of them here and when and what orders to give them. Having said that, you'll still want to keep at least two of them alive while you're in combat just in case you get armor-locked by a member of the Covenant that you didn't notice before. Just be prepared to do a lot of this work yourself if your team develops a sudden case of the crazies.

From here, take out the Plasma Cannon gunner while your allies deal with the second Warrior. You'll also want to keep an eye out for the Plasma Cannon on the far right platform just in case a wandering Grunt or even an Elite decides to use it. You also need to make sure you're doing this from the very back of the walkway as going forward too far will trigger the second wave of enemies, overwhelming you entirely. After the Elites are down and no one is manning either of the Plasma Cannons, focus on the shielded Jackals and Storm Jackals lingering about on the platform at the other end of the walkway. Once you're confident you've dealt with all of the enemies thus far, walk forward just far enough to pass the first platform on the left, then immediately turn and head back to the area from which you came.

The second wave is now in effect. It won't contain much, but what it does will be VERY lethal too you. Among the three new enemies you'll have to deal with will be a Jackal Sniper that will be parked on the first platform to the right of the walkway as well as a Ranger Jackal that will be on the platform on the far right. Take them out carefully, but you'll also want to be quick about it because the third enemy is a cloaked Special Ops Elite who's not only cloaked, but is also ruthless with his sack full of Plasma Grenades. Don't worry. He'll come to you. Just make sure, like before, that your allies are between you and him. As soon as he engages them, light him up!

With the area now finally safe, and can proceed to the platform at the far end of the walkway. On the left side will be another Warrior Elite (your top priority here) along with additional Grunts and Shield Jackals. Start mopping up the cannon fodder, and as soon as the Elite shows his ugly head, paint him for your teammates. When the area is clear, you'll notice a series of platforms up ahead leading to your exit. And on those platforms? You guessed it. More Covenant. At least it's only groups of Grunts and shielded Jackals. Nothing you can't handle.

At this point, you'll want to go back and retrieve the Sword dropped by the fallen Special Ops Elite. Trade out your Plasma Pistol for it and make haste towards your exit. There will be two seemingly fallen Hunters here that are about to regenerate and become a serious threat. If you're fast enough, you can use the Sword on one of them as it's getting up to put him back down on a more permanent basis. As for the second one? You'll need to utilize the Fuel Rod Cannons from the crate on the right side platform. Take one for yourself, and give the other to one of your squad mates. Use the platform for cover while you paint the Hunter for your allies to deal with instead of you. Take a moment to empty your Fuel Rod Cannon into it, but remember to hide once you start getting shot. Between your team's grenades and the other Fuel Rod Cannon, they should be able to make short work of the final Hunter.

When both Hunters are down, send your allies to the now open elevator where a squad of Grunts will be waiting for you. Nothing to crazy fortunately, but they still love throwing those Plasma Grenades, and this late into the mission, better your allies than you. With the Grunts down go ahead and scavenge the area. Replace your Fuel Rod Cannon with the Plasma Caster on the opposite platform and head inside the elevator with the rest of your team.


Things apparently went to hell in a hand basket while you were downstairs. The city is now burning, and out in the distance, the Guardian is beginning to rise from the sea. Things get a bit crazy here. You can melee one of the dying Covenant to get your shields back before proceeding forward. You'll want to tread carefully though since the platforms and buildings are quite literally beginning to crumble as they fall into the ocean.

Keep making your way across the ruined city until Locke nearly falls into the water via a short quicktime event. Then, jump down to the lower level of the building directly across the gap, head up the debris to the top floor, and you'll be treated to the arrival of the Prometheans in Sunaion. Go ahead. Laugh it up as a panicked Grunt is being pulled apart by Crawlers. Head through the door and be treated to the sight of the Arbiter assassinating a helpless Knight. We have another boss battle ahead, but at least this time we have the Arbiter there to help us. Well, at least until he gets knocked into the sea by a storm of Splinter Grenades.

This is how the next battle is supposed to work. Prometheans will continue to spawn in various places across the battlefield. You'll be dealing primarily with Soldiers and Crawlers. You can control the spawn closest to the back of of the area (where you'll be most of the time) by temporarily advancing to the right side tower down the hill below. This will stop the Crawlers from spawning in that area, leaving it as a safe fallback position. First, however, you'll want to deal with the two Watchers that are flying back and forth. Take them out now so they won't be a problem later. Now make your way over to the right side tower closest to you. A gravity lift will be there to take you to the second floor. Up here, you'll not only have an excellent vantage point to target to Prometheans further down and away, but also there's an additional Plasma Caster up here along with a Covenant infinite ammo crate!

My advice here is that you target the Soldiers one at a time, and try to divert as much attention away from the Arbiter as possible. Using his Prophets Bane Energy Sword, he can cut the time of this battle down by a lot so long as he isn't knocked into the water. That's the only way he can "die" here. Also make sure your allies are all using Suppressors to make the Soldier mowing go MUCH faster with your allies not dying so much. Use the Plasma Caster to help weaken the Soldiers. And while the Soldier waves have a set number, the Crawlers can spawn in infinitely. Also don't be afraid to take cover as often as you need. Your allies can't reach you up here to get you out of armor lock which is the only real danger involved with this strategy. So be extra careful!

The final wave of Soldiers will consist of mostly Captains with Splinter Turrets. Once you take them down, you'll here the familiar call of the Warden Eternal. An additional Watcher (along with a pair if Knights) will spawn in with him. Don't worry about the Knights, but instead focus on the Watchers. Once they're down, you can focus on the Warden himself.

While the following method may take some time, it works AND it's safe. You don't have to go anywhere near the Warden. Just stay on top of your little perch. All you need to do is repeatedly fire Carbine rounds at his face. When you run out of ammo, use the infinite ammo crate to replenish. Rinse and repeat. It's that simple. Granted it will take hundreds of rounds and several minutes, but considering that you've reached the end of the game's most challenging mission, I'd say that "safe" is the best way to go. On the fifth armor rupture, his body will be sucked back into slipspace and the mission will end.

You can finally breathe. It's all downhill from here.

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Home | Halo 5 Mythic: Days Gone By | Skullpocalypse | Keep Your Friends Close
But Keep Your Enemies Closer | Lock And Load | Hitchhiker's Guide | General Tips and Tricks

Osiris | Blue Team | Glassed | Unconfirmed
Evacuation | Reunion | Swords of Sanghelios | Enemy Lines
Battle of Sunaion | Genesis | The Breaking | Guardians
Halo 5 :Guardians LASO Challenge