Hey guys!
I am playing a lvl 73 Spellbreaker (https://www.grimtools.com/calc/RVvL5QpN).
I have 80% Vitality, 80% Bleeding and 70% Chaos Resistance with 8,000hp and okay def rating and health regen.
I have had no problems whatsoever clearing the content up to this boss. Yet somehow I cannot get past Thalanos. He has an ability (Chaos Bolt maybe?) that one-shots me. From 8,000 hp to 0 with 70% resistance. Is there a tell when he will use this ability? Or is my build just completely messed up?
Have a look at the monster db and you can see that Thalonis mostly does Chaos and Fire for which your Resistances (36%, 47%) are meh for Ultimate.
Also he has an ability that further shreds resistances and spawns pets that shred aswell.
Your armor is low and only has 76% absorption meaning your already low armor only works 76% of its power. DA is low, you are probably getting crit consistently. (OA is abysmally low but that doesn’t affect your defenses too much).
You don’t utilize the arcanist skillset pretty much at all. There are many defensive tools there aswell (Maiven, Arcane Will, Mirror, Nullification (not strictly defensive)).
Your build currently tries to go both caster and melee. Focussing on one usually yields better results. For Spellbreaker as a class caster performs better as it utilizes arcanist as a class better. You probably want to use TSS at one point or another if you want to go the caster way (You got conversion for it aswell).
Hey jrc, thank you for your answer!
I forgot to say that I am playing on Elite, not on Ultimate. Also I noticed that my resistances are shown differently than what they actually are ingame. My actual ingame resistances are 80% for bleed, fire and vit and 70% for chaos. I don’t know what else I can do to improve my armor - the items that I have equipped pretty much have the highest armor value of all the items I found, same goes for my DA. My build can obviously be optimised, but for now I wanted to try a hybrid version with caster skills and autoattack procs - but this inefficiency should still not allow him to onehit me 
I’m on my phone so I can’t see your devotions, but which have you taken?
Amatok, Tsunami, Ghoul, Spider, Murmur, Behemoth
Does OP have solemn watcher?
EDIT: I think behemoth isn’t very useful on a breaker. If OP could squeeze in crab, that would be tight.
nope, he’s missing blue for that aswell
Yeah. Behemoth is probably the least high yield of all the devotions. His OA needs to be way higher too
EDIT: of all the devotions mentioned
Up your armor absorption to 100%. Simply change components.
You havn’t used augments at all. That can help upping your stats significantly
Edit: Overload yields a bit of free aether resist aswell, Phantasmal armor yields armor
I think you need to be revered for armor augments, but jewelers augments should help.
Armor absorb isn’t gojng to help against thalanos, however. It’s not physical damage
Is he using maivens? What about mirror/BB?
None of those, see my post above
Edit: BB acually yes
Apologies. I’ll be home soon. I’ll reply then. Thanks for the help jrc! <3
https://www.grimtools.com/calc/r2BnqMb2
Try this. Changed up the augments on your spec.
Btw, like it or not, a breaker is a CDR based nuker. So you might to get starpact asap
I will give it a try, thanks guys!
no problem. try shard of beronath instead of coldstone if you can craft it