Stakar Ogord, the One Who Knows, used to share his body with his wife. They both took the identity of Starhawk. Due to their past history, Aleta and Stakar had a sort of contempt for one another, and did not wish to let the other emerge and take temporary possession of the body. Finally, they were liberated when their individual bodies were restored and they were no longer forced to resort to sharing one body.
Starhawk I 36

In issue #5 of GIANT-SIZE DEFENDERS we saw as the freedom fighters of an alternate future, the Guardians of the Galaxy, traveled back to the Defenders' time, where they met Guardians leader Vance Astro's younger self, the boy known as Vance Astrovik. Later Marvel stories would show how the Vance of the present day would reach a "point of divergence" between two alternate timelines. In one alternate timeline he would grow up to become Vance Astro of the Guardians. But in "mainstream" reality Vance would take a different path, in which he is now known as the teenage super hero Justice, a member of the New Warriors. The Defenders team accompanied the Guardians of the Galaxy to their far future time, where they helped the Guardians win their first major victory in overthrowing the alien Badoon, who had conquered the Earth of that time. During this storyline Gerber gave the readers a grand overview of this alternate future, establishing the futures of DEATHLOK and KILLRAVEN series as part of the same timeline as that of GUARDIANS. It was also in this multi-parter that the Guardians first encountered Starhawk, an enigmatic costumed man with vast cosmic powers. Readers also met Aleta, Starhawk's equally mysterious mate, who cared for his children. It would remain for the GUARDIANS' own forthcoming series to reveal that Starhawk and Aleta had somehow fused into a single being, and only one of them could manifest himself or herself in the physical world at one time. This was a variation on the situation in which Captain Mar-Vell and Rick Jones had found themselves. In this case Gerber appeared to be devising a symbol for the duality of male and female sides of the same being, or perhaps for the union of two people in love; Aleta and Starhawk had indeed joined both emotionally and physically.