If Hendrik's asking around about the most influential Summoned in Thorne, Ronan's name is probably one of the first he'll hear (likely in the same breath as Kylo Ren). He's pretty easy to find around the castle, since everyone knows what he looks like and can point him out, but Ronan's just as likely to approach Hendrik first to extend him the same offer he gives to every newbie. If you're interested!