Lord Haart and how to get rid of him!?

How can I prevent Lord Haart (with the Estate specialty) from appearing when building a map in castles? I've already set it so that heroes can only be recruited in their home castle, there are no castles on the map, but the hero still appears. He's also not in the hero list.

Hmm... that's strange. Maybe it's some kind of bug?
However, if you remove (uncheck) it in the editor, he shouldn't appear in the recruitment list.

In the worst case, you can lock him up in a prison and make the path to the prison inaccessible. I can't think of any other solution for now.