And now I'm towards the end of book three in the series and... Arvan is just working out he has Yuan-ti blood in his veins... So, got my wish, kinda.If the mind seed did its thing, Arvan would be effectively dead and his mind replaced with a copy of Zelia's mind including all her knowledge. And his body would still be physically human. It doesn't change a person's species. It's the potion that does that.
Thanks for reading.