Yoshimitsu, Manji Hero

Combo 6, Flying, Toxic 1
Seppuku (When this creature attacks, you may give it +3/-3 until end of turn,
but sacrifice it during your next end step.)
Fatal blow (When you declare combat, you may double Yoshimitsu, Manji Hero's power
and deal damage
to target creature equal to its power, but it doesn't untap during your next two untap steps.)