Defeating Ir Yut involves taking down several powerful enemies on both sides of her chamber, before entering and evading the attentions of her colleagues long enough to take her down. And if you don't do it all fast enough, she sings you to death. Good times. This all follows The Thrallway and the second raid chest, so if you've skipped ahead, check out that first.
How to defeat Ir Yut, the Deathsinger
Although you still have to take out Ir Yut before summoning Crota for the final showdown, this area is where the rest of the Raid takes place. Get to know it. You start off at the bottom of a pit that's reached by dropping down a hole at the end of the Thrallway, which then leads you out into an arena set on three levels.
On the ground is an altar along with lots of Thralls and Knights. Climbing stairways on the left and right-hand sides of the arena takes you up to a platform that loops round the edge of the battleground, and includes an indoor section on the near side - accessible from left or right - which is where Ir Yut is hiding. Then, in the far left and right-hand corners as you enter the arena, there is a further pair of even more elevated platforms, which you can use for defence in the Ir Yut fight and which also play host to dangerous foes when Crota arrives.
You can take out Ir Yut in a couple of ways, depending on the composition of your fireteam. If you are all very powerful (e.g. level 31) with maxed-out expansion weaponry (e.g. 331 damage), you can probably split up into two teams of three and deal with the challenges on both sides of the arena simultaneously. If you are less certain of yourselves, you can deal with each challenge in turn as a larger group, but this guide will assume you're splitting up.
In either case, the idea is to destroy the Shriekers located on either side of Ir Yut's central chamber. Each Shrieker is defended by two powerful Knights and a Wizard, all of whom you will need to slay before attacking them. Once the Shriekers are down, the forcefields containing Ir Yut's chamber drop and you can blow her to pieces.
To make matters more difficult, if you don't do any of this quickly enough, Ir Yut will start the Liturgy of Ruin, which lasts 30 seconds and will wipe your team out if you don't kill her before it finishes. The countdown for the Liturgy is actually a good bit longer and begins once you enter the arena, so it's important to move quickly right from the get-go.
To begin with, everyone needs to get to the raised platform running around the edge of the arena. To do this, run out of the door where you start, past two Knights guarding the main area, and towards either of the staircases hugging the left and right walls of the battleground. Three of you should go left, three should go right. You don't need to kill the Knights. Avoid double-jumping until you get to the top of the stairs and the enemies on the ground floor shouldn't follow you up. If they do, they should still go back down after a spell - just don't rely on it.
Two players on each side should go up to the safety of the higher platform in the far corner of the arena. The remaining players should run indoors and bait out the Wizard lurking near Ir Yut's chamber. The Wizard will chase you outside flanked by a pair of Knights. Kill them all, doing the Knights first.
When the Knights and Wizards are down, you need to take out the Shriekers, which are attached to the ceiling very close to Ir Yut's chamber. Race inside and jump around laying heavy ordnance on them. Once they are both down, you can start tackling Ir Yut. Rockets are a good idea here - we told you Gjallarhorn would be useful - and be very careful to stay on the move and in the air, because more Knights will arrive and start hacking away at you.
If you find that you're struggling at this point, it may be an idea to concentrate on doing the Shriekers one by one. Their death blasts often cause problems and as long as the Liturgy of Ruin hasn't begun, you have a bit of time. You can help yourself out by using Hunters' invisibility to evade mob enemies, and if Titans on your team have the Helm of Saint-14 exotic helmet, the Defender sub-class's Ward of Dawn bubble will blind any enemies who enter it, giving you a safe zone within the rooms leading to Ir Yut's chamber.
Don't relax once Ir Yut is dead, because you still need to clear out some of the remaining enemies. The threat of the song has passed, though, so it's safe to fall back and regroup before concentrating your fire on the various mobs who gather round her chamber. Once you kill enough of them, the rest disappear and you're ready to take on Crota.
It didn't originally, but these days taking out Ir Yut also rewards you with Raid loot and the chance of exotic drops. We got No Land Beyond one time. FML.
Next up, and finally, How to defeat Crota, use the Chalice of Light and survive Oversoul. Good luck!
You can find the rest of our Crota's End guide from the first page of this article. You can also read the rest of our Destiny guide, or when ready to play year two content, our Destiny: The Taken King guide.