88 vs. 100% vpip player and unkown

[geormiet]

live 100200

I have a tight image and have been losing a lot, but i really doubt either player in the hand is aware of this. BTN is niko, he has close to 100% vpip and doesn't make too many moves postflop except will always get to showdown or at LEAST the river. The BB is mostly unknown. He is quite angry, semishortstacked, I saw him play one hand where he had QQ and value bet it all the way vs. 3 other players on a Kxx board in a capped pot.

I raise 88 in mp, niko calls, bb 3 bets, i call, niko calls.

Flop is K54 rainbow and bb forcefully bets. I decided to call, niko calls behind me (he can have anything, would also call a flop raise with anything)

Turn is a 9, and bb bets very quickly again. Fold? raise? Call?