Saving Grace

Pure damage redirection, packaged as an Aura, with the redirect happening exactly once on resolution rather than as a standing effect. That timing detail is the whole instruction set: the enters-trigger snapshots the rest of the turn so that anything aimed at you or your board, a swarm of attackers, a sweeper, a burn spell to the face, gets funneled onto a single creature you have deliberately propped up with the +0/+3. Flash is what turns it from a curiosity into an ambush. You hold it until combat is declared or the spell is on the stack, drop it on a blocker fat enough to eat the incoming, and watch an alpha strike collapse into one lump of damage on one body. The redirect is unconditional: because it replaces all damage to you and your permanents with damage to the enchanted creature, even trample stops mattering, since there is no "excess over the blocker" left to spill onto you. The single point of failure is elsewhere. The enchanted creature is now absorbing everything, so a deathtouch source anywhere in that pile kills your wall, and the redirect is locked in for the turn whether or not the math works out: overcommit the sink and you can still lose it to damage you invited. Build the sink first; the Aura only matters once you have something worth pointing the turn at.