True Conviction

Double strike and lifelink are individually unremarkable team-pump effects; stacked on the same enchantment, they multiply into each other. Double strike does not just add a combat-damage instance, it doubles it, and lifelink reads every point of that damage, so a board swinging under this can gain life equal to twice their total power while dealing twice their total power. Those two numbers are the whole point: the card converts any committed board into a single attack that often ends the game and refills your life total past the reach of the counterattack at the same time. That feedback loop is what the steep triple-white cost and six mana are paying for. This is a finisher that demands you already have the battlefield it rewards; with an empty board it does nothing, and against a sweeper it sits there as a six-mana enchantment doing six mana of nothing. The card answers the gap between "I have creatures" and "I win," which is exactly where white aggro and go-wide token strategies tend to stall. Where Overwhelming Stampede or a one-shot anthem closes a single turn, this stays on the table and turns every subsequent attack into the same lethal-and-stabilizing swing: less a combat trick than a switch you flip once and leave on.