Nightcrawler - Kurt Wagner
The origin story starts off with a love affair between Mystique Azazel whose ultimate plan was to have babies on earth, so he can get out of the dimension known as brimstone.
When he was born he struck fear into everyone because he looked demonic, Mysrigue tried to kill him and cover up her tracks, but he could not die thanks to his father who would not allow him to die. Has he grew up his powers started to grow and that's when he joined the circus to perform shows.
Professor X saved him from been killed by a mob of people and that's when he asked him to join the X-Men