Soul's Grace

Lifegain pegged to the opponent's biggest threat reads like a clever idea: the more dangerous the creature, the more life you bank against it. The problem is that the two events never line up. Against a small board, the gain is trivial and the card is dead; against the fatty you actually fear, you spend a card and two mana to stay alive one extra turn while the creature that earned you the life is still standing there, ready to swing again. Nothing about the spell touches the board. Targeting your own creature is technically an option, but white has more durable ways to convert power into stabilization, and an instant that only buys life buys the most perishable resource in the color. The instant-speed window is the one redeeming wrinkle: held up as a combat response, it can blunt an alpha strike after blockers are declared, padding your total against the very attacker you read correctly. That is a narrow use for a card that asks you to evaluate the battlefield precisely and rewards you with a number rather than a solution. This is filler-grade lifegain whose ceiling is capped by the same mechanic that makes it sound exciting: the spell scales with the threat, but never removes it.