How to Destroy the Sarcophagus in XCOM 2: War of the Chosen
So you’ve made it to the ascension room within the Chosen’s stronghold and are face to face with their sarcophagus, what now? That thing is just going to keep reviving the Chosen over and over, so you’re going to have to take it out. It’s definitely smart to focus your energy and resources on that and deviate your attention from the random aliens that keep spawning in. They won’t stop, but the sarcophagus will steadily revive until the number at the top right reaches 100%. Take out any big threats, but definitely focus on the sarcophagus. Once you destroy it, you need to kill the Chosen one last time.
You might encounter a weird glitch where the health of the sarcophagus won’t go down. This is unfortunate, but it’s not entirely game breaking; just very annoying.It wasn’t until the Chosen was revived twice that the health seemed to have reset and I was able to do damage. You can wait for that (increasing the difficulty of the mission by, like, a lot) or you can reload your save. It’s definitely not normal, is what I’m saying. You’re supposed to do immediate damage to the sarcophagus once you’re able to attack it. You can see this in subsequent strongholds that you’ll attack.