Undead Summoning

As an additional cost to cast Undead Summoning sacrifice X creatures and discard X cards from your hand. Can't be countered. Chose three (you may chose the same mode more than once) *Target player sacrifices target creature they control, if X is 5 or more they sacrifice three target creatures they control instead. *Target player discards 3X cards and puts the top 3X cards of their library into their graveyard, if X is 5 or more they discard 5X cards and puts the top 5X cards of their library into their gr