Simic Keyrune

Hexproof is the design tell here. Across the cycle of guild mana rocks built to animate into bodies keyed to their guild's combat identity, this one wakes up as a 2/3 Crab that opponents cannot target, and that protection maps onto the colors it serves: the pairing that wanted its threats to outlast removal long enough to matter. So the animation is built to slip past interaction rather than punch through it. The body it becomes can't be answered with a spot removal spell on the turn you flip it, which makes the artifact a fixer that doubles as a sticky blocker or attacker whenever you have both colors to spare. Note what hexproof does and does not buy: the Crab survives removal, but it carries no evasion, so it still trades or stalls in combat like any vanilla 2/3. The cost structure keeps it honest. Animating demands a colored on top of the lands you played, and the shell fades at cleanup, reverting it to a defenseless artifact that you re-pay for each turn you want the Crab back. As ramp it is slow and taps for a single color; as a clock it is modest. The point of the design is the split: fixing when you are short on lands, a hard-to-kill body when you are flooded, with neither half pushed far enough to overshadow the other.