Just looking at a log where groups of storm giants were all targetted at a treant, which they couldn't hurt.

Is this balanced? I can understand treants being imm blunt vs players, but against mobs it seems a bit much, even if it makes for easier coding.

Maybe others consider it fine though, hence my asking, but a tank that's immune to a wide variety of mobs seems a little strong. I'd argue my case like this:

Mobs don't get lagged by players because mobs lag other abilities, like the ability to run away. Similarly, a player would run away if he was unable to do anything against someone. These mobs just stand there until they die, despite the fact that it is clear that they can do nothing. Therefore, I would enable mobs to treat imm blunt as res_blunt.