Horserider Soul

When horserider soul enters the battlefield,
conjure 3 cards named dead s willing onto target
player s library (to conjure a card, put that card on
the specified zone. It is treated as if it was there
always. Dead s willing is a sorcery that costs {b} and
has Target opponent reveals his or her hand. You
choose a nonland, non-spirit, non-arcane, non-demon, non-angel, non-dragon card from among those. That
player discards that card).