I've played a few hundred hours with Enigma. It's a great legacy.

To your specific question, intelligence matters as has already been pointed out. Someone in the know would have to confirm, but it seems to me it only matters as to whether or not you get a successful "zap" off. Then, maybe, if the spell in the wand checks your intelligence to determine success it matters it matters there too.

My comment though would be that I personally (for whatever my personal opinion matters) consider the use of offensive wands an ancillary benefit. Primarily, I take Enigma for two reasons, one is to be able to escape combat without fleeing and the other is so that I can change size on the fly. Secondarily, it can occasionally be useful to heal/prep as you're fighting.

You probably know all that and have a specific wand you've found you want to use -- but I figured I'd share just in case.