Urianger’s most powerful healing spell works by having his patient suckle the healing juices from his fat wizard tits, and he uses it to save Thancred’s life after the last fight with Ranjit. And any other time Thancred may need it. Or maybe if he just wants a little sip, y’know?

Please envision the Warriors of Darkness, newly brought to the Source after the Flood of Light meant they were in a situation where their only hope is an ascian offering to help them via ritual suicide. They know Cylva was a traitor. Everyone they knew is probably going to die, and soon. They trust Elidibus as far as they can throw him, and as far as they know, Urianger is his loyal lackey.

[…]

It turns out that Elidibus is attempting to recruit just the right Scion. Urianger is driven by his hope that he will find a solution to whatever dangers the Star is facing and his desire for the salvation of the Source and First alike. Given Elidibus’ true nature this is an absolute feast, and he would very much like to keep the elezen with him, be it through knowledge, promises of eternal life, physical and mental pleasures. (And if he can keep the man focused on hope and salvation all the better.)

Urianger, for his part, wants Elidibus to believe he’s entirely loyal to him and is acting the part. And a part of him really is enjoying Elidibus’ company, lessons and attentions when he can push aside the gnawing guilt.

Bonus points for mind games, sexual use of magic, claw play.

(If you want to go for the bad end: feeding a primal who wants you to be absolutely loyal to him is a dangerous game.)