Raphael recognizes and becomes obsessed with the orb in Gale's chest... and slowly becomes obsessive/possessive over the wizard as well.

+ Raphael getting extremely jealous if Gale starts a relationship with a companion. Maybe even watches them have sex (pairing up to you)
++ Gale not seeing the massive red flags but maybe Astarion can
+++ Raphael saving the party from an almost tpk. Gale's death belongs to him.
++++ Raphael fantasizing what he's going to do when Gale is finally his. (Up to you if this remains a fantasy)