[quote=@Antarctic Termite]
<Snipped quote>

Just happened upon this rule somewhere that I haven't seen [s]or maybe been paying attention to.[/s] Given that Osveril is Purity (Voids) and Jvan is Beauty (Voids), I'll probably start writing Jvan's portfolio as Beauty (Negatives) with pretty much the same powers.
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The same powers as your original idea, or the same powers as Osveril's Portfolio? If the former, that is fine (unless it overlaps too strongly with the latter). If the latter, then they'd still be the same Portfolio (or sufficiently close) (eg. Teknall's Smithing and Conata's Metalworking, while having different names, are exactly the same thing). This would provide no problems unless/until Osveril ascends.