One thing that really pushes my buttons is when you're pumping vitality on each level up, and you level up while your max HP is drained, the current max HP is increased but not the base max HP. This forces you to choose other stats lest you waste your points. Around the midgame when you're running into tons of akatekos, if you're a melee character you'll be perpetually drained of max HP (yes I know you can safely destroy packs at a distance by linking with each hand one at a time but I still end up with drained max HP somehow, also that feels pretty cheesy anyway) and you'll not be able to make full use of vitality on the level up. I don't know whether this is intended or just an oversight but this has been around for a while and it's just so annoying.
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In the 5/3 build, I've noticed that certain enemies without max HP stealing abilities will spawn with bonus max HP, this is an intended feature since their negotiation demands might include taking some max HP right?
But then that means they should either be a minion, or if it was a failed negotiation and they killed the summoner, they most likely would've lost that max HP from the negotiation during the fight. I dunno it just seems weird because it isn't obvious as to how they got that max HP.