MHR Sunbreak Magnamalo Strength Hammer  

Either final boss or Magnamalo deviant hammer (MR100) but Final boss works better (350 raw and A LOT of purple sharpness) honorable mentions to BOB hammer and kamura hammer

It's very good sharpness wise but the final kamura hammer is probably the best for set making in general, you can also use elemental hammers with charge courage instead of charge strength

Swapping from purple to yellow charge gives you s

Yeah. At the start up, I believe.

signifcantly more than a normal roll. It's a really good option to things and reposition at the same time.

Also nice to trigger an extra knockdown if you wanna run hellfire mantle (as it is a wiredash). Not saying it's optimal, just generates a nice knockdown chain between the usual KOs and partbreaks