Eidolon: To start: The most recent incarnation of Eidolon, in various costumes, member of Superior-X (a franchise of the X-Corporation)

His story: Born without a soul, the void within was replaced by the outcast archangel Uriel. Has superhuman strength, an arcane sword, symbiotic armor and the ability to sprout wings from his back. When the wings sprout, his hair and eyes turn stark white. When he first donned the armor, it took the form of medieval composite mail, and later a more Spawn-like form. In fact, he is a Spawn, but  with slightly different origins.  

Me, with my Superior-X shirt Medieval armor Spawn armor
Spawn in flight

Superior-X (Eidolon [me], Syndicate [power draining & military training], Swagger [stunt driving.. also transforms into Monolith], Alloy [think T2], Kronos [time-controlling ninja], Skye [Scottish Jedi] & Monolith [living gargoyle])

Round 2: Before converting to the Ultimate universe, Eidolon had a few different incarnations.

The first was simply a telekinetic, power-thieving phaser with bi-polar disorder and paranoid tendencies. His powers were artificially imbued upon him by an evil group of super-scientists (before his mutant abilities could manifest themselves). After skipping from one X-group to another, he finally settled with the up-start X-men off-shoot, Superior-X.  He died (the first time) phasing through an overpowered Apocalypse, thieving a bit too much power than he could handle.
Eidolon reborn (and renamed: Oberon). It was revealed that had his DNA not been meddled with to give him his former powers, he would have discovered that he was, in fact, a Werebear. Unfortunately he only lived for just over a year before a rampaging Doombot sucked his soul from his body into a Soulgem... very sad.  

Out of sheer generosity, and gratitude for retrieving his renegade  Doombot (yeah, right), Dr. Doom constructed a Darkforce-powered Doombot android for Eidolon's soul to reside in. His new android body granted him new Darkforce powers.. his particularly favorite stunts included: Darkforce tentacles, bat-like DF wings, shifting into the DF realm (particularly to "teleport"), and storing objects in his DF "pocket" (a secured section in the DF realm where we stored his weapons and valuables). He had no hair, eyes or need for clothing.. all were constructed from pure Darkforce. (Doom also had various surveillance and failsafe devices installed in the android).

While attempting to construct an alternate (female) android body for himself, Eidolon created "Lilith Anais". However, he found himself unable to control when he shifted bodies, and also was unaware that the experiment was a (limited) success because when his soul entered the female body, a suppressed (female) personality emerged. This alternate personality was aware of Eidolon, but he was not aware of Lilith. Eidolon and his girlfriend, Danielle Fishel.

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