Halo Infinite Legendary Difficulty Boss Guide

Let’s get started.
1. Weapons
You may think that anything other than a high damage hitscan weapon like a sniper rifle is useless. This is not true. Carrying 2 heavy weapons into a fight will not guarantee your success. The first key in defeating all of these enemies will be first and foremost;
-Killing surrounding fodder enemies
-Depleting a boss’s shieldsThis is where high damage per second (DPS) and accurate small arms weapons will pay off. I’m not saying to not bring heavy weapons, but your best bet is to stash them somewhere memorable in the zone, so you can come back to them later. Remember also that you can swap weapons continuously to transport more firearms to the Boss’s zone.Weapons to use:
Sentinel Beam -Accurate, holds a lot of ammo, good for killing fodder enemies

Commando Rifle -Accurate, insta-headshot kill on unshielded unarmored fodder enemies

Machine Gun Turret -High damage, high DPS, no overheating, can continuously stagger bosses, good for draining boss health and keeping them from closing space

Power Cells -Ridiculous range. Use these as grenades, they will insta-kill all unshielded fodder including butes with direct hit, and will save you from expending valuable ammo, these are also good on bosses

Dynamo Grenade -Using them in conjunction with heavy weapons like a rocket launcher or hammer can mean the difference between being cornered by thirsty shielded fodder or grappling away at the last second

Weapons to avoid:
Hydra -Don’t bother with this weapon, its damage output is laughable, its capacity is awful. You will regret choosing this even over a pistol, even on grunts

Plasma Turret -Will stagger a boss, but will overheat instantly

All vehicles except for Scorpion Tank -In the few scenarios you can access vehicles, none of them last long enough to do anything. They can’t strike bosses for damage, don’t try except for escape

Ravager -Awful weapon, not worth it in legendary

Energy Sword -”Wait, what?” yes, don’t use it. You might be able to score a few lunge kills on enemy fodder, but not having an area-knockback effect like a Gravity Hammer will mean a close encounter with anything stronger than a fully shielded elite may make you a dead Spartan

The Bosses:

Tremonius -Test of Mettle: 6/10
This fight will set the stage so you understand what you are in for. This fight is difficult because it’s hard to predict what weapon he will use. It’s best to always seek cover, trying to keep distance while taking out his Jackals as you go. If you are able to take out all the Jackals, you will have peace of mind, but this is not always possible.
Use whatever weapons are in the room to drop his shields. Incidentally… I happened to kill him by punching him what felt like around 20 times. I don’t know if that is supposed to be possible, but I was able to perma-stagger him in a corner, when his shields were down. He moves rather slowly, even with his jetpack lunges, they are predictable. Stay behind cover though… he has a skewer and even a sniper rifle sometimes, and he knows how to use them.

Chak ‘Lok -Test of Mettle: 7/10
This will be your first test of your finesse against a cloaked elite opponent. Use your grapple timings wisely. I suggest you start putting points into the Threat Sensor, if you haven’t already. I completed this with no modifications to the Grapple, so you may find this battle slightly easier.
There are many power cells dotted around the corridors of this zone, using them is in your best interest, as throwing them at least close to where you think he is will stagger, and reveal him momentarily. Careful of using sticky grenades, he is fast and can rush you if stuck. Luckily he seems to be vertically impared, so a quick grapple to the ceiling can save your life.

Bassus -Test of Mettle: 8/10
This is your first Hammer wielding boss to whom even Tartarus would cower under their presence. This will also be probably the first boss where you think this may be truly an impossible feat. Bless your heart. Do not stand still, nor strafe in place for too long, his hammer lunge is an insta-kill no matter if you think you dodged it. If you’re able to see his feet leave the floor, it’s already too late and your fate is sealed, Spartan scum. Your best choice from the start is to launch an opening volley of a heavy weapon, then instantly grapple to one of the two rooms on either side of the control room. If you are lucky, you can grab a power cell on your way and grapple again to the far side of the room, and face the entrance. Your goal here is to put enough distance between you and him that you are able to shoot him/load him up with grenades as he’s entering the room to meet you. May your headshots shoot true. Before he’s able to get within striking range, grapple past him, back into the control room, and quickly repeat the process in the opposite room.

Adjutant Resolution -Test of Mettle: 5/10
Thankfully, something easier. This is a conventional boss fight, he will not be happy and you have to kill him. Hide behind cover, shoot his weapon arms off, and jam a grenade in his eye socket when he shuts down. That’ll show him. Avoid his charged eye blast.

Tovarus and Hyperius -Test of Mettle: Impossible/10
I still refuse to believe this is possible. I refuse to believe anyone used conventional means to kill these damn apes. You try to kill their fodder enemies; they kill you. Try to hijack the ghost; they kill you. Try to steal their chopper and run away; they one shot you right when you think you made it out alive. You have no backup, there’s no bases to order up a tank, nothing. The problem is you can’t deal enough damage to just one of them before they attract the attention of the other, take cover in a dangerous structure, or both. They can snipe you from the highest mountain top in the blink of an eye. They. Are. Invincible. I don’t know what to tell you here, it can’t be done. For your health, I recommend not trying, and turning the difficulty lower. How did I do it?
I was somehow blessed enough to have one of them lunge at me, hit a berm, and fly away, glitching a mile into the atmosphere over a mountain ridge, sniping at me, but never to be seen again. Luckily, I hit a savepoint, and was able to kill Hyperius out of sheer luck, leave, return, and Tovarus had re-appeared. I then killed him. Both were merciless, and I still died as many times as I had in the entire game once over at least, just in this battle, even with the glitch.

Adjutant Resolution (again) -Test of Mettle: 7/10
He’s back, and he’s mad you bullied him in highschool and wants revenge. Pretty standard again, only he has friends… Best bet is to pick up a Shock rifle or a Stalker rifle, and use them to two shot the incoming Sentinels. Don’t let them pile up, make them a priority kill as soon as you see them. Once again, stay behind cover, and use the grapple wisely to get to cover. Memorize the locations of ammo fillups. Beware his sweeping missile attack, even behind cover, you may not be safe from splash damage. Respectable strategy might be to use final shots to destroy one of his limbs right as he is starting a missile attack, as it will shut him down hopefully before he can blow you apart.

Jega ‘Rdomnai -Test of Mettle: 8/10
I hope you’ve been upgrading your grapple. This enemy is near impossible to see, and does all together disappear from existence between heated assaults. This will test your hearing ability, I applaud you for using surround headphones during this part. Power cells function well like in Chak ‘Lok’s fight, although they are sparse. This enemy seemed particularly vulnerable to high DPS weapons once his shield is down. Shotguns, grenades, rockets, anything with a spread or splash will help in revealing him, staggering him, and dropping his shields. Most of the time I reckon, you will be running from him. Once you hear his footsteps, grapple to the furthest possible wall and attempt to spot him. There is no high ceiling, so beware trying to go straight over him. Dropping down levels can be key to making an escape to catch your breath. But I believe I finished him off with an assault rifle.

True tests of a Legend:

Escharum -Test of Mettle: 9/10

It’s time. You’ve heard his stupid voice too many times, and you’ve had it with his dad trying to flirt with your purple girlfriend in your dreams. Your new A.I. lady will guide you to find his weaknesses. I suggest saving a few heavy weapons in reserve for when his final battle happens after you destroy his shield generator. There should be a Skewer, maybe even a rocket launcher in a supply shelf in a corridor. Use any means to damage him as much as you can at the start of the battle. Once his shield generator is online, swap guns to something cost efficient like a Pulse carbine to shoot the reactors. The moment his shield drops temporarily, bonk him with the best heavy weapons you got. Try to conserve grenades, you will need them for the power move.
Once his final reactor is blown, be in a good position to stick him with as many grenades as possible while he is staggered. Then run! For those of you who have been upgrading things like evade, you may find this more easy. However, I did this while only using a mildly upgraded grapple, and Threat Sensor. Once you get him to below a third health, time to finish him off. Go find the machine gun turret, it will be laying in a section of the corridor, against some junk. Make sure he’s at a safe distance, and open fire. This will continually stagger him and hopefully, drain every hitpoint he had left. Then, steal his hammer, and hold onto it until you meet the Harbinger..

Harbinger -Test of Mettle: 10/10

You aren’t a Legend yet, the fight isn’t finished.
This battle will test how your patience has fared. If possible, bring a rocket launcher, and by the Prophets, I hope you brought Escharums special hammer. The fodder enemies you have to battle in between fighting off the Harbinger are horrible in their own right. It may not seem that bad, a light wave at first, and then a second wave of a handful of Elites, Brutes, and Skimmers. However, it’s the second wave you will spend the most time on.

Start the battle by killing the first wave, they will be typical enemies. There are various supply racks around the room that hold Cindershots, DO NOT USE THEM (don’t use Escharum’s hammer either!), at least not on the first wave of enemies, they are too valuable and need to be used on the Harbinger. Instead, lure the enemies close enough to the supply racks so that the moment they are all killed, you can immediately swap one weapon for a Cindershot, while still carrying Escharums hammer. The moment the last enemy is killed from the first wave, the Harbingers protective barrier will drop. Shoot her as many times as you can rapidly with the Cindershot, until her shields drop, then, nail her with the hammer. Now for the second wave.

This is hard. Your number one goal is to kill all enemies but the shielded brute with the hammer. Wait for one of the doors to open, kill the enemies inside by any means necessary, and hide in it. Throw a shield, and wait for them to come, they will come fast. The moment you see a skimmer, throw a grenade, anything. They will devastate you with Dynamo grenades of their own. There is no easy way to take out all these enemies, just beware the shielded brute, and beware the elite who has a sniper. Once the brute remains, hopefully your game saved. I found the best way to kill him was to use a Sentinel beam on him, drop down from one of the platforms as soon as he catches up to you, have him jump off to follow, then quickly grapple back up. He will have to run back up a ramp to follow you, so just shoot him and repeat the process.

Now, once the brute is dead, quickly use the Cindershot on the Harbinger again, this time using cover to avoid her ranged attack. Once she is staggered, finish her off with the hammer.
Godspeed Spartan.