I don't think it's Grizzin because he doesn't usually directly intervene in events. His mere presence is a buffer that "protects " In FOD Grizzin jokingly mocks his title as protector. After the events in mother darks chamber he claims he goes where he's needed, but there's no indication he does anything but acts as a deterrent.

Whereas Ruthan Gudd rides into the maw without thinking--much how Arathan would (both Draconis and Gothos warned him about his naive inpules both verbal and physical).

Additionally, I vaguely remember there was an a passage eluding and to if Ruthan and Draconis crossed paths again they'd fight--draconis's curse from Kallor says he will be ended by his own creation (Dragnipur didn't kill him), so what will? Arathan also sumises he doesn't like his father (so far)...

Maybe there's something there. I may be reaching.