Yoshimitsu

Haste, First Strike, 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.)