Healing Tears — At the beginning of your end step, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of life you gained this turn.
Celestine turns lifegain into recursion: gain life each turn, then at your end step reanimate creatures from your graveyard whose mana value is at or below the life you gained. Build around big lifegain swings to bring back larger threats, sacrifice fodder, and value creatures repeatedly for grindy mono-white attrition. Win by overwhelming the board with recurred bodies, aristocrat drains, or a recursion engine that opponents can't keep up with.
Free reanimation every turn that snowballs once lifegain is online
Lifelink on a 4/4 flyer that fuels its own ability when she connects
Mono-white consistency and access to powerful white staples and tutors-lite
Excellent in attrition matchups; out-grinds removal-light tables
Mono-white card draw is poor, leading to flooding and topdeck dependence
Healing Tears only triggers on your end step, so it's slow and removable
Needs both lifegain and graveyard fodder online to function
Vulnerable to graveyard hate and board wipes that strip her engine