10. Selene – 17,000 Years Old
The Hellfire Club have caused more drama with the X-Men than Magneto’s brotherhood, and that’s thanks to their involvement during Chris Claremont’s famous Dark Phoenix saga.
Selene is thought to be over 17,000 years-old, claiming to have already been old by the time man was first taking steps. That’s pretty old, and with all that experience to go off, it’s no surprise that Selene has been a figure of authority for both man and mutantkind for dozens of centuries.
Selene is also said to be the progeny of Greek Titans Hyperion and Theia, so her origins have mythical roots too.