Hmm, I think a bit of fresh air sounds good right about now!

[There's really no reason he has to be a dog. They could go out with him as himself. He's not sure whether Yona even considers this as an option, but... eh, he won't complain. It means he less likely to run into someone who might recognize him.]

[And so he poofs!! into a cute little doggie again.]

You should be careful not to exhaust yourself too much. Overwork is poison for the mind -- your ability to use magic for longer periods of time will grow over time, but you shouldn't try to force it either!