Mouse Trapper

Valiant's core problem is that it asks you to spend a spell or ability targeting your own creature, and most white designs with the mechanic pay you back with a static bump: a counter, a keyword, a temporary buff to the creature you already control. This one converts the trigger into interaction with the opponent's board instead. Point any pump spell, any aura, any activated ability at it, and you tap down a blocker or attacker on the other side of the table. That reframes what the target is worth: the buff you cast is doing double duty, and the tap can happen on the crackback turn as easily as your own. Flash is what closes the loop. Held up during your opponent's turn, it lets you flash it in and later target it at instant speed to tap a creature out of a blocking assignment, or to strip a tapper or utility creature at a moment of your choosing. The 3/2 body is priced to attack into the tempo you are generating rather than sit back, and the valiant clause resetting once per turn keeps the tap on a dependable clock. It is a small piece, but it points the whole valiant idea outward: the reward for targeting your own creature is not a bigger creature, it is a worse turn for the person across from you.