Realizing there was not point in lying, Mika sighed. "I guess that's up to you. I've never done this to anyone before, and I sure don't want to change someone nice that doesn't want to be changed." He flushed. "Well, I mean, not all the way. I figure this much is mostly all good, right?"
The centaur grinned as he looked back at his equine self. "That is a true statement, lad. I've been suffering from aches and pains in my horse half for a few years, and they are all gone. I'm old for a centaur, though you humans don't realize it. We stay in our prime longer, but when we hit our 40s we go fast. I'm 43, and I was feeling it. Another year or two and I'd have been white haired and feeble."
That surprised Mika, though now that he thought about it, centaurs did mature faster and seemed to look the same for a long time. "I'm glad to have helped you out, sir. But you'd better get out of here before my master comes back."
"He'd finish me off and do the same to you, right?"
Mika nodded grimly. "Yeah. You'd better go."
"And leave my new best friend to suffer? I don't work that way, boy. If I keep my memories and identity, being a beautiful draft horse doesn't sound bad. On the other hand, you could run away with me now. Or I could probably use all that same magic on you and make you into a beautiful draft horse." The centaur shifted around so that he was facing Mika and tousled the stable boy's hair. "I'm open to whatever you want. You can use the brush to finish me off, climb on my back, or hand me the brush."