(I do not own My Little Pony)
Aurora Borella is my idea for a alicorn OC. She is the alicorn of the Northern Lights and is responsible for panning of the Northern Lights. She is most know for her rather bad attitude, but she is not a bully and will tolerate most ponies if she feels she has to. Aurora tends to keep other ponies at a distends, even living in an isolated watched tower on the outskirts of the Crystal Empire. Aurora Borella dose not hold any royalty title or position of power by choose. The only responsibly she will willing take is one she already has, that of the Northern Lights mostly do to lack of motivation.
I imagine her to be pale green or midnight blue with light blue eyes and pink, purple, and red hair that she keeps in a pony-tail or just keeps it down and rarely brushes it.
(I'm sorry for any spelling and grammar errors.)