I'd like to think the writers might be playing the long game with the Triad story. If Regula is to become a Kefka-esque character then it would be somewhat anti-climactic for us to defeat him as soon as he acquires the Triad's power. It would be a lot more satisfying IMO if he got what he wanted then defeated us, only to go on to become the primary villain of the Garlemald expansion pack or something.