A Dead Flames Wrath

Commander Ninjutsu {u}{b} ({u}{b}, Return an unblocked attacker you control to hand: Put this
onto the battlefield from your hand or the
command zone tapped and attacking.)
Whenever a Ninja you control deals
combat damage to a player, reveal the top card of
your library and put that card into your hand.
Each opponent loses life equal to that card’s converted mana cost.