Of course!!

Callanin is the President (read: dictator) of Velana, which is the country on Vuliros that Acentel and Imerial are in. He's a very traditional Vulirosi guy and he's very anti-church. Through the uprising and eventual coup that he was head of, there's been a big shift in Velena to bringing back a lot of the traditional Vulurosi ways from before the church came to Vuliros, and a lot of that involves rights for quadfolk in general and specifically the right for people not to be forced to maintain elfshape in order to exist in Velenian society. Because of all of this, the Sliasistic Church has been moving leftward in a frantic attempt to maintain control, including appointing the first non-elf to the highest office within the church (the pope equivalent, which I know I gave a proper title but I can't find that in my notes right now.)

Callanin himself is an ex-military guy, and maintained elfshape for a long time. He's notably huge, and even in elfshape he's over 7 feet tall. I'm still working out all the details of his backstory, but the main important parts are his relationship with the previous royal family and Antanaia.

Velena used to have a royal family, which was appointed by the church. The title of king would still be handed down to the king's offspring, but the church could strip them of their power and titles at any time, and for many centuries would just straight up execute them. Antanaia's family had been in charge of Velena for a while, but they were falling out of favor with the church and were at risk of having their titles stripped. Antanaia was really interested in what Callanin had to say about the political system and the church, and ended up helping him with the coup. They eventually wed (in the traditional Vulurosi style of course) and had a baby named Taliv.

Callanin's power went to his head pretty fast, and though he holds a lot of ideals that we'd consider leftist, he ends up being a very authoritarian ruler. Antanaia is not a fan of that, which is why they decide to leave him. Taliv still lives with her father because she's a daddy's girl through and through.

Callanin has a pretty important role in the major world events going on in Saints & Machines so I won't get too into where his plot is going, but I will say that he's good friends with Urale, which will be a thing that causes a lot of pain and suffering later on down the line. :^)