Varragoth, Bloodsky Sire

Tutor effects have almost always been sorcery-speed and unconditional: pay the mana, find the card, done. This design attaches the search to combat instead, and that reframing is what earns the card its study. The Boast clause turns the tutor into a reward for pressing damage, and because Boast can only fire on a turn the creature attacked, the ability asks you to commit a 2/3 deathtoucher to an attack before you get paid. Deathtouch keeps that math survivable: it deters trades and lets the body poke in even against larger creatures, which is exactly the risk a repeatable tutor needs to avoid being free. The subtler wrinkle is the target: "target player" means the search need not point at yourself, opening a line where you set up another player's next draw as a bargaining chip or a political favor. Boast as a keyword ties its payoff to the act of attacking rather than to a static board state, and this is the ability that showed the mechanic's ceiling. A tutor is the most flexible thing black can hand you, and stapling it to a mandatory attack step converts raw card selection into a question of how much you are willing to commit to combat each turn.