Soul Heart

Soul Heart is an incredibly potent snowball ability that transforms Magearna into an increasingly dangerous special attacker as the battle progresses. Every time any Pokémon faints during the match—whether it's an opponent's Pokémon, a teammate in doubles, or even Magearna itself if it gets revived—Soul Heart triggers and boosts Magearna's Special Attack by one stage. This cumulative effect can rapidly escalate Magearna's offensive presence, making each knockout more impactful than the last.

The ability's scope encompasses all fainting, creating strategic depth in both singles and doubles formats. In singles, Magearna becomes more threatening with each traded KO, potentially reaching devastating Special Attack levels in longer games. In doubles, the ability shines even brighter as teammates' fainting can still fuel Magearna's power, and the faster pace of knockouts accelerates its scaling. The Generation 9 text clarification specifying "another Pokémon faints" doesn't actually change the mechanical function—Soul Heart still triggers when Magearna itself faints and is subsequently revived.

Competitively, Soul Heart makes Magearna a formidable late-game sweeper and a constant threat that opponents must carefully consider when making sacrifice plays. The ability synergizes perfectly with Magearna's excellent Steel/Fairy typing and impressive special movepool, creating a Pokémon that becomes exponentially more dangerous as battle casualties mount on both sides.