Brimstone Vandal

The day/night mechanic gave designers a rhythm to build reward triggers around, and this Devil is the one that punishes the shift itself rather than the state. Note the wrinkle in how it arrives: if neither day nor night exists yet, it establishes day as it enters, which means the first flip it participates in is one it half-authored. From there, every transition in either direction pings each opponent for one. The clock it runs is passive and asymmetric: opponents who want to avoid the ping have to keep the cycle frozen, but the mechanic tends to swing on its own from casting patterns (a turn with no spells tips toward night; two spells tips back). What makes the design coherent is that it does not care which way the wheel turns, only that it turns, so an aggressive board that keeps flipping the cycle drips damage regardless of who is technically "winning" the day/night tug of war. Menace on a 2/3 body keeps it relevant in combat while the transitions accumulate reach, and the two abilities point the same direction: pressure that does not require the Devil to connect. It is the kind of card that turns a set-wide state mechanic from a bonus into a resource, taxing an opponent for engaging with the very system it thrives on.