Mardu Devotee

Two jobs stapled to one white one-drop: it digs the moment it lands, then settles in as a repeatable color-fixer. The scry 2 on entry is generous selection for a creature this cheap, and because it triggers on entering, the dig happens whether or not the body ever swings. The activated half is the quieter design work: for one generic mana it produces red, white, or black, precisely the Mardu wedge, but it nets zero mana. This is filtering, not ramp; you spend one to get one back in a color you actually need. The once-per-turn clamp paces the fixing rather than capping the mana total, since the ability could never accelerate anything no matter how often you activated it. What earns the slot is the 1/2 body doing three things across a game: it blocks the aggressive one-drops it would otherwise trade poorly against, it survives a stray point of damage while it fixes, and it lingers as a filter you can lean on turn after turn. This is fixing-as-creature done with restraint: enough value bolted to a survivable frame that the inclusion never stings, and no engine hiding underneath for a game to warp around.