Hawkman and Hawkgirl
Species: Human/Thanagarian
Enemies: The Raven, Dr. Psycho, Fatality, Parallax, Prometheus, Queen Bee
Hawkman and Hawkgirl are very compelling characters. Their story has switched up a bit over the years but the most popular version has the two date back to ancient Egypt. Carter Hall or Hawkman is the modern-day reincarnation of the Egyptian Prince Khufu. Yet he is also connected to the alien police officer, Katar Hol from Thanagar. Yet Hawkgirl is the reincarnation of Egyptian Princess Chay-Ara. Due to the several versions, it is hard to keep up. Yet there is a similarity among them all. They might die but they’ll always be reincarnated.
The goal for their life is to find each other, which could take some time to accomplish. A common merger is to buy into either form of reincarnation but also connect them to Thanagar due to a meteor that initially killed them from that planet. That ties them to the alien race and also explains them always being reincarnated. It can be missed that the two are among the most powerful galactic characters though. Their species is tough enough due to their super strength, ability to fly, and impressive weapons and armor. Add in a form of immortality and that takes them over the top.