Why not make an item of it?
Or we could learn Scintillating Scales and use an item of Alter Self, which Lya has already begun making in the Greater Ribbons of Disguise.
Talking about items with spells, next turn we should consider crafting Viserys a Book of
Spell Knowledge.
There are so many great spells we could add to his repertoire for very cheap, even if we just used spells Lya already knows or has access to from unread scrolls or fellow spellcasters.
Each 1st level page would only cost 75 IM; 300 for 2nd level, 775 for 3rd, 1200 for 4th, and so on.
Here are just a few of Lya's Arcane spells we might want for Viserys to have access to:
1st level: Ant Haul, Comprehend Languages, Heightened Awareness, Keep Watch, Protection from Evil, True Strike
2nd level: Animalistic Power, Cat's Grace, Detect Thoughts, Glitterdust, See Invisibility
3rd level: Alter Fortune, Great Thunderclap, Slow
4th level: Enervation