Felidar Sovereignfinisher$3.62A white alternate win-condition creature that also cares about life totals, though it wins instead of setting an opponent to a specific number.
Aetherflux Reservoirfinisher$19.20A powerful life-total-based finisher that can dramatically swing the game by leveraging life gain, similar to Magister Sphinx's life manipulation impact.
Tainted Remedyutility$6.96It interacts with life-gain and life-total changes in a way that can punish opponents, creating a similar life-total swing dynamic.
Soul Conduitutility$0.63This artifact directly exchanges life totals, serving a similar high-impact life-total manipulation role.
Peer into the Abysscard_draw$2.43A black spell that massively alters life totals in a dramatic, game-warping way, though it targets one player rather than setting to a fixed number.
Sorin Markovutility$7.41His loyalty ability can set a player's life total to 10, making him the closest functional match to Magister Sphinx's signature effect.
Tree of Perditionutility$12.03Another creature that manipulates a player's life total directly, replacing it with its toughness for a similarly swingy effect.
Lord of the Voidfinisher$12.00A large evasive black creature in a similar high-end threat slot, though it focuses on card advantage rather than life totals.