I have a couple of questions about the dungeon?

My father is a pain in the neck so as we were playing and i drew the dungeon keeper and i had at least 4 followers and I had 5 gold. I lost 4 followers and bought them all back.....felling it was a ransom. My father said it was a penalty and I lost all my follwers and it was up to the next charector who landed there to have the oppertunity to buy the followers?

We over ruled him and played it like a ransom. How do you play?

Also, I had a follower (Dragon) that I had Dominated with a spell.....What happens to the Dragon? And what would happen to the follower (Dragon) if i had it under anything that could enslave an enemy such as the staff of mastery? Does it come back to life or does it go back to the discard pile and do you have to fight it or does another character that lands there have to fight it ?

Thanks,

Freybourne