For Vardy:

He is the lion formerly known as
Prince King of the Ianga. Now he's a slave... and he couldn't be happier! You might not notice, he's a rather sullen guy, but really, he is happy.
He has a similar outlook in that he only wants to do the best for everyone. As a king this made him a somewhat ineffective ruler, because he always tried to please everyone and was always unwilling to sacrifice for the greater good. There's no such thing as the ends justifying the means in his world view, a belief he holds especially strongly after the war fiasco. The reason he's so happy to be a slave is that for the first time he's able to work from the bottom up, helping only one person at a time, just the way he always wanted it. Maybe he could provide companionship for Vardy or try to help him see his new position in a different way.