I got a true infinite with urso engine, then quit b/c lost data when switching computers, then I had an elemental+bulky infinite run, which I willingly quit for the spring costumes events, I think you can have two fused items on ur monsters, get your items up to +3 then fuse them for cost efficiency and maximum ability power boost. Krog is great in infinite with his bellow ability, Wyrmlet's magical acceleration is epic, and lots of other fun strats exist like mudgill shattershard