This boss i pissing me off, I get to the part where he goes under water and goes on the outside of the arena but I always die, im a humar level 14 using the dark deo arm.
try using a shield press L to block. Shield is the most useful weapon to use against a boss. you lose PP everytime you block an attack or stock up on some monofluid
Just keep hitting him with everything you got. I can't believe you still can't beat him at level 14....
Use a Long-Range weapon, like a Cannon, Handgun, or Mech Gun like I did. When he changes to a closer position, switch to some Daggers and hammer away.
Make sure you have 10 Dimate and 10 Monomate, equip the best equipment you can buy for now. It'll help if you have a Scape Doll too.
wait till he sucks you in and keep running, disregard partners because they suck and they're slow. keep smashing his head till he enters the outer ring. avoid his tentacles and ink spews by keeping far, but not too far because he spins the damn dock like a dj scratches discs. when he sucks you in, resist until you're close when he stops so you can get in a few hits. rinse and repeat, and he's dead
When he goes on the outside it doesnt matter just get teammates to all out attack witht the tactic thing and have star atomizer to stay alive. I did this with FOMAR and daggers which is sad as shit.