That was another aspect to consider; if Ares had broken this man and left him alive, he'd done it for a reason. How pissed would Ares be if Apollo undid his handiwork? Where did that fit into their truce?
Apollo gave Cin a long, considering look. She walked in here like she owned the whole city, pointing at a man she knew was a god and commanding him to fulfill his promise, this mortal like a piece of dynamite in a very delicate crack.
If she hadn't been asking Apollo to heal her boyfriend, when that was entirely the role that Apollo wanted for himself, Apollo would have loved this. Yeah, get up Ares' nose, fuck him! After all, the truce had really only protected each other's people from harm, not healing.
And really - all of this was just static on the wire. He'd promised Cin he'd do anything for her. He couldn't back out of that promise. He loved her too much to back out of that promise.
"You're right," he said, silencing a string of swearwords in his head. He'd only just got his strength back! Fucking dammit! "I'll do this for you."