There is something in the back of Diabhall's mind that's needling him - he can't put his finger on what, precisely, but it manifests occasionally in his having to will his hands not to clench tighter around Loki, in his chin lifting just a little more proudly than it ought to.

Instead, he focuses on the question. A variable he has control over.

"Well, in the case of a Warlock, a deal is made between a powerful being and someone aspiring to that power. The terms depend on what the entity wants. In the case of my Patron, I promised him knowledge and study, and in return, he would grant me magic."