Serra's Boon

A color-axis design exercise wearing the clothes of a pump aura. Holy Strength gives you +1/+2 with no questions asked; this stitches the same buff to a condition, granting it only while the enchanted creature is white. Aim it at anything else and the aura inverts into a Weakness-style debuff, dragging the creature to -2/-1. What lifts it above a curiosity is that the color clause is a static ability checking continuously rather than locking in on resolution: a permanent can change color mid-game, and the effect recalculates on the fly. Hit a white creature that loses white to a color-changing effect and your own buff curdles into a liability; conversely, a nonwhite creature later painted white flips the curse into a gift. That live re-evaluation explains why the switch is color rather than, say, a fixed creature type: only color is volatile enough to swing under outside influence. It belongs to an experimental, color-pie-shifted design era that asked what spells would look like if white inherited red and black's appetite for punishing creatures that aren't its own, and answers by stapling reward and removal to a single aura with the target's color as the toggle. The caster knows exactly which half they are casting the moment they choose a target: white means buff, anything else means shrink. The genuine cost is downstream, because anyone with a color-changing effect can later turn the aura against whatever its owner intended.