Sacré-Cœur

Cast this spell only if you control a legendary Assassin.
Choose a non-token creature you control.Target opponent chooses a non-token creature they control. Those creatures are the duelists.Each duelist’s controller exiles the top X cards of their library. The duelist whose controller exiled cards with the greatest total mana value wins the duel.The controller of the losing duelist loses life equal to the total mana value of cards they exiled,then sacrifices that duelist. If the totals are tied,each du