After beating Verga like a bad stepchild and banishing him back to his home city to sit and lick his wounds, I decided to demand his surrender. He accepted. Thus I inherited a new champion, an immobilized one stuck in the midst of black fog-of-war (FoW) map space that I'd never gotten around to exploring. OK. I figured that's a leftover situation from him getting immobilized as my enemy previously.

I waited out Verga's deep freeze and expected when I got full control the FoW would vanish around him. It didn't. I had to make his first move completely blind to the surrounding squares:

Once Verga moved, the FoW went poof and lifted.

There's one more strange artifact happening here. Normally units moving outside of cities will have an icon for their army in the units area on the left edge of the main map. In this case Verga didn't get one after he surrendered to me. I was able to move him normally but he never got a units icon before I quit for the night.