Its a critical step for white weenie decks to keep pace, and also as backup in the face of a sweeper spell like Anger of the Gods
Its also worth noting that other cards with the support ability (like HeiHei above) state that the target must be another chosen character (meaning the supporter cannot select itself), however Merlin does not specify
Costing one generic, one white, and one blue, she's also got a multikicker of either blue or white in a cute flavour win
As much as this is an Eldrazi, I would rather play Counterspell over Ulamog's Nullifier, cheaper and simpler
I see this being pretty damn playable, especially in versions of those decks that make treasures, can ramp with green, or can do big mana stuff with devotion and cards like Cabal Coffers
This Alpha artifact, released in 1993, offers an incredible ability: "Tap to gain an additional turn." While the card originally required skipping a turn as a drawback, clever deck-building soon turned it into a game-breaking combo piece