Whooaa. Iinteresting. Somewhat scary.

Feels like it should perhaps be red, the colour of fast mana and the second colour of instants-and-sorceries.

I think it fits better in blue here for a couple of reasons:

• While red is the color of fast mana, it is not really the color of permanent mana acceleration, which this is.
• There are a couple more redouble cards in blue than in red, which was meant to be one of the "hidden" interaction this card had (allows you to actually hit the expensive extra costs for redouble). Prodigy also doesn't help much with casting Arc Flame.

Basically, this is the blue version of Somberwald Sage. It was originally just , but just felt a little underwhelming. Does seem pretty powerful with any of the Pulses, but if someone manages to assemble that in Limited it feels like it'd be a source of sweet stories anyway.