When Legion was added to Timewalking the spawned adds in his fight that apply the debuff that detonates on their death, Seed of Corruption-style, weren’t scaled down and they were doing damage as if the players were level 120 which resulted in one-shotting the player and anyone close enough to be hit. I personally saw entire groups insta-wipe over and over due to this, making him unbeatable at times.
It seemed to have eventually been fixed, but it’s back. Just got out of a regular LFG group in the dungeon and we were getting one-shot by the explosions again. We only managed to get passed him on our third attempt because he only summoned one and the explosion “only” took out two of our group and the rest of us were far enough away and he didn’t summon anymore of that particular type before we got him down.