The uncommon blue Geass could alternatively be a Mind Control variant.

Ooh... or a Betrayal, since that's got great flavour - Lelouch Geassing an enemy member to unknowingly inform on enemy movements to him.

Misplayed this; twice. "That someone else controls" is kiiinda important and easy to forget. Maybe the art can fix that? :)

If control-change is a significant theme in the set, then perhaps we should remove the "an opponent controls".

Though in a game against Neil, it was actually handy that if I borrow the creature using something else, the Geass falls off, letting me use a different Geass on the creature! But that doesn't make much sense, so that still argues in favour of removing "an opponent controls".

That's making this quite a bit better than Betrayal, and might need the cost to come up, sadly.

What would the cost of the not-opponent-restricted version be?

­Curiosity is still one mana, but gives you the card later on in combat. Ocular Halo and Oracle's Insight are 4 mana and Quicksilver Dagger is 3, but those bypass the combat step entirely. Prophetic Ravings and Epiphany Storm are 1 mana but loot rather than drawing.

I'm going to guess 2 mana is probably fine. It's possible that 1 is fine, actually, but that kind of tweak can wait until I find out the relative power levels of the colours in the set.