AKA, a Celesteela and Mismagius fusion. These are two of my favorite Pokemon, and after seeing someone else's try at combining them, I decided I'd do my own take.
Name: Tetsumagi, from tetsu (meaning Iron) and magic.
Ability: Levitate, Magic Guard
This incredibly rare Pokemon has been known to soar across the sky at night, riding its rocket as if it were a witch on a broom. The rocket remains in Tetsumagi's vicinity at all times, held by some invisible force.
It has become common folklore that those under the possession of a Tetsumagi are guaranteed prosperity for a time, thus making it highly sought-after.
Tetsumagi generally enjoy feeding off of the sense of wonder found in those who see it. When threatened, it uses its rocket to release terrifying bellows of fire in every direction, before making its swift escape.