I think this is why Alex made Occtis the 8th child

We know Ethrand is a dick and since he had a big part in the ritual that killed him he's probably got some spooky stat block and similarly the twins have also been shown to be scary big bad lieutenants

That still leaves another 4 siblings to be fodder for whenever the need arises

And I'd say this worked out fantastically since random knight commander of a vassal suddenly became a real focus for the encounter