If hybrid can have Arrows of Justice and Fire at Will, presumably hybrid could have an attacking-or-blocking restricted version of Douse in Gloom / Essence Drain?

Oh, good question. Probably?

I'm not sure how much "Fire at Will" is justified by "red very occasionally gets direct-damage to attacking/blocking" and how much by "it's a subset of direct damage". I think the latter means it's balanced but may or may not be thematically in-pie. I guess maybe even wizards are winging it.

Conversely, this would be very amusing just as a mono white spell. White clearly gets "damage to attacking and blocking" and clearly gets "gain life". But does it get them together? Not because it's a forbidden effect (cf. peculiar distortion etc) but because white doesn't do "drain"... :)