Hask the Fallen Son and palm foliage

This doesn't apply only to this boss fight but getting killed because you he's parked himself under palm foliage that completely hides his actions and movements so that you can't react to his one-shot attack is ridiculously bad design especially when your beloved XP loss is more than happy to strip away hours of play.

It's 2025. Most games render visual obstruction transparently so that they won't obscure things a player needs to hit.

Lastly, there is something fundamentally wrong with the change in 0.3 where every map has a boss but the availability of broad defense (resistance, armor, ES) is poor from the campaign leading up to the endgame. At the entry point of the endgame where defense is still poor, character death is essentially guaranteed when even white mobs have enough crit to take a player out or bosses all have one-shots and the stage itself camouflaging and blinding players for that sweet GGG kill.