Drain, as an 8th level necromancy spell (costing 40 production to put into a potion) does the exact same thing that Enfeeble does, costing 30 production to put into a gas globe to throw, without the illegal consequences. And in fact seems to be slightly better than drain, in that enfeeble specifies crawling speed, where drain says walking speed. Just throwing my two cents out here, and there are probably things I'm not considering such as which effects affect what things etc. etc. But drain seems like it could/should be a scarier effect for its level. Like adding in disease's "no effect from healing" or something of the sort, cuz right now drain just seems like an illegal reskin of enfeeble.