I think there has been a lot of progress. They are in the same cage, although Mimo is scared and shy and meek now, and Castielle seems a little bit obsessed with his new power and occasionally gets SUPER puffy and hops/sidles fiercely next to Mimo. Mimo spends his days hiding and will allow soft pets of his little face.
We did schedule a castration for Castielle for next Friday, as they do still have about 2 all-out no-holds-barred ratball fights per day, after which Castielle is removed to the time out cage, since he loves to pick fights. They tend to fight more when there are a lot of hidey holes in the cage, so we removed the huts and left hammocks, tubes, burrowing blankets, hanging foam snuggle nests, etc. We also give Castielle treats when he approaches Mimo and decides not to engage in any alpha behaviors (sidling, puffing, rump nipping, chasing, etc.) and are slowly seeing Castielle become more friendly towards Mimo.
Mimo doesn't have any bite injuries that we can see, but they have both scratched each other on their faces during intense boxing matches.
Toward me, Castielle has been a giant lump of sweet fuzz since Mimo got home. No biting, no cage aggression and some of the very first snuggling that I have seen. I am feeling especially fond of him right now because he cuddled under my hand while sleepy and seemed to very much enjoy having his face stroked, neck scratched, ears rubbed, etc.
Now, I'd really love to see Mimo come out of his shell. He is such a beautiful little boy and I feel like he would be very shy and sweet if he decided to like us and feel comfortable exploring the cage rather than hiding and burrowing in blankets. We are both still slightly nervous around both of them - esp. Mimo, who still likes to "mouth" (nibble with mouth open as he sniffs), which I'm scared will turn into a chomp.
What is the best way to woo little Mimo and help him to become a little fuzzy lover instead of a scared, shrieking boy?