I did sine math with his skills he gets a pregnant permanent 103% boost to explosive damage and 140% when in FFYL. that's not all though, bloodlust stacks give him 1% per attack with a certain skill. with a max of 100 stacks he gets 240% boost to explsive damage while in FFYL.
kreig is going to be a beast.
Search Kreig Full Skill tree if you wanna see his other skills.
Oh, you thought they made this game for you? You clearly bought the wrong game.