Preceptor Seluvis

Meet an ethereal Seluvis in Ranni's RiseGrace after speaking to Ranni.

Head South to Seluvis' Rise to find the real Seluvis and get Seluvis' potion. You can either give the potion to Nepheli Loux to poison her, turn it over to Gideon Ofnir, or use it to poison the Dung Eater. Your choice does not affect the next step.

Find Seluvis' secret room in the ruins near Ranni's RiseGrace and read the message there.

Speak to Seluvis and purchase all of his sorceries, plus at least one Puppet Ash.

Find Amber Starlight on Altus PlateauGrace and bring it to Seluvis, and receive the Magic Scorpion Charm. You can either stop here and continue with Rannis quest, or continue.

Deliver the Amber Draught to Ranni, which will turn her hostile

Absolve sins by using a Celestial Dew at the Church of VowsGrace in Liurnia