Leo uses 4 buttons. It has all of its moves from "Teenage Mutant Ninja Turtles Tournament Fighters", and they are all done the same way as the source, even the Hyper Move. There is a possibility that it uses Kung Fu Man as a base, if some of the file and animation names are considered, but it plays nothing like said character, aside from having four buttons.
In terms of Leonardo's moveset, it seems as if it is loosely based off a shotoclone. "Shining Cutter" is equivalent to the Hadouken, and "Roto Cutter" is similar to the Shoryuken.
Leonardo's A.I is brutal and aggressive, making it a difficult opponent for beginners.
Hovering the mouse cursor over the Command Input icons will display text that refers to the inputs set in M.U.G.E.N's Key Config.
Icons encased in square brackets [ ] require the respective button(s) to be held down. Hovering the mouse cursor over the icon displays the hold duration if applicable.