Invulnerable Enemies

Bug Report ID: #1923274394

Ever since the update ~a week ago, I have encountered several enemies that stop taking damage. These enemies are always rare or unique, but have no visible modifiers or bonuses that would make them immune to damage. I have noticed these monsters in end-game maps, rogue port contracts, sacred grove, and in the main campaign areas. The most recent one, in the sacred grove, was the unique boss Namharim, Born of Night. It's health was lowering rapidly, then stopped. It stayed invulnerable for over a minute no matter what I threw at it. I exited the grove and re-entered. No change. I exited the map, then re-entered the grove, no change. In the previous areas I found the invulnerable monsters, I just moved on (as I will do here). It is fairly annoying that the monsters bug out like this. If anyone has experienced anything similar, please add your experience.

Edit: I decided to go back and test things by kiting it around. Eventually, it transitioned to the tree-state and started taking damage again. This is the first time an invulnerable enemy became vulnerable again. Could it be due to animation lags? Or AI behavior?

Those Harvest bosses go through a phase like that where they become really tanky and can appear to be taking no damage when all the spawns happen, not sure exactly how it works, but I've felt like it was invulnerable some times, I think it is part of the mechanic, but maybe it gets stuck phasing or something.

On the other ones, it might be related to your build but unsure. Could be a separate thing to the harvest boss or something related.

It's hard to say exactly without seeing. If mobs are out healing your damage they can seem like they are invulnerable. If they are like you say, stopping taking damage at some point, like getting them low and then hitting a wall on damage it might be something else.

There are mobs that don't take damage under certain conditions. For example, certain mobs in delve will not take damage in the darkness. Expedition mods clicking in that make things immune or near immune.

I don't see anything on your build that would cause this, but with rf/firetrap, maybe mobs are getting an increase to fire res somehow. DOT can get countered by healing mechanics as well. Might be kicking in at low life or something. You could try frost bomb on these mobs to see if reducing healing makes any difference.

I'm aware of the harvest boss transition phases. I've seen it multiple times, this isn't that. It reminded me of how when you're facing Daresso, no matter how much you damage him between phases, he heals up to whatever scripted life he's supposed to have for that phase. The creature simply stopped taking damage. It wasn't until I led it around the stage that it suddenly remembered that it's supposed to transition into the tree-root thing. Once that animation happened, it immediately started taking damage again.

I'm also aware of the darkness mechanics in the mines. I have not yet encountered this bug anywhere in the mines.

If it helps to clarify, I've been playing this game since Piety was the final boss. I know a fair bit about how the rare mobs work. I'm not an expert by any means, but I start to get suspicious when mobs, who have no visible signs of invulnerability, suddenly become invulnerable.

I don't stream, nor do I have the ability to show what I've seen, but my friend was playing with me a few days ago and witnessed it happen. One of the rare mobs in a rogue mission before alert bar was full, an orb alerter (they fly around and make rings of light that don't damage) was losing life until about 65% through and suddenly stopped taking any damage. Nothing he nor I threw at it did anything anymore. We eventually decided to ignore it and move on.

I know that life regen can counter DOT damage, or any damage for that matter. Please don't mistake me, I am not talking about difficult creatures that regain life. I'm talking about creatures whose health bars stop moving entirely. They have no visible heal mechanics or aren't supposed to have healing. I know some creatures have base mechanics, but this isn't that. It's creatures that are not supposed to be able to heal or go invulnerable, who are becoming invulnerable for no reason.

This has happened to me during bosses too. Bosses that I've fought several times before, with a weaker version of my character. They become invulnerable for a time, sometimes I have to restart the game and then re-enter the maps for them to start losing HP again. It's obvious to me that it's some kind of bug. I'm sorry if I'm not explaining myself clearly.