difficulty 4

When I battled then I killed the scorpion thing first then killed the vajra last if you know where the scorpion first shows up it helps a lot.

I've taken things a bit differently with multiple bosses up to now and barely made it out alive. Somehow I beat Scorpion and Vajra together, then later Scorpion and two Kongous. There is a mission that will require you to kill four Kongous at once. They all four respawned where I started and I had literally nothing left when they all fell.

Anyways, after that warstory, advice for survival. Bring your strongest weapon against them (with type advantage) and your sturdiest shield. If you don't see a weak spot, make one. You'll do a nice extra load of damage. Burst mode offers a bonus so use that whenever you can. The bullet usually isn't helpful because your boss is resistant to it but you still get melee bonuses. Finally, I can't stress this one enough and it isn't a weapon or fighting tip either. Your psychological state affects how you fight. ALWAYS look at a boss and keep the state of mind that you are hunting the monster, not the other way around. You will kill it. Now start swinging your blade.

during late game, when its you vs 1 aragami, i use the flash bangs to sneak in a few devours. really helped against the black hannible battle.