Skitterskin

The regeneration clause is the whole interplay here: a 4/3 that can't block looks like pure aggression, but the activated ability flips it into a sticky attacker that survives sweepers and combat trades, provided you've committed to a board of colorless bodies. That conditional ("control another colorless creature") is doing the deckbuilding work. It tethers the regeneration to the Eldrazi-and-colorless theme rather than handing it out free, so the card only earns its resilience inside the strategy it was printed to support. Devoid is what makes that conditional reachable in the first place: it strips the creature of color entirely while leaving the black mana in its cost untouched, so Skitterskin is a colorless creature that happens to demand black to cast. That distinction matters in both directions. Skitterskin itself counts toward the colorless-creature requirements of its allies, even as it asks for a separate colorless body to fuel its own regeneration. Built as a midrange beater for an aggressive colorless deck, it reads as a humble curve-filler until you notice the symmetry: a creature funded by one color but belonging to none, leaning on a board of devoid and Eldrazi cards to keep getting back up while it pushes damage it never has to spend blocking on.