Captain Universe

Within Marvel Comics continuity, the Uni‑Power is presented as an extra‑dimensional energetic emissary that emanates from a larger source called the Enigma Force. Sources describe the Enigma Force as connected to the Microverse; modern continuity notes (in-universe) that the Enigma Force was created by Celestials as a reaction to Knull, but other summaries caution that the exact nature of the Enigma Force remains an enigma. The Uni‑Power manifests by selecting and empowering hosts "in a time of crisis," transforming them into the persona called Captain Universe.

There is no single fixed visual design for Captain Universe because the Uni‑Power superimposes a costume and heroic traits over the existing appearance of its host. Hosts typically retain their original personality and basic appearance while gaining the Captain Universe costume/effects. Documented hosts range widely (examples in sources include Spider‑Man, Doctor Strange, Bruce Banner/Hulk, a toddler, and a dog named Casey), and the visual presentation varies accordingly; recurring motifs are a distinct energy-costume overlay and heightened heroic bearing during the episode of empowerment.

The Uni‑Power empowers a chosen host with a broad suite of cosmic-level abilities and a near‑endless supply of energy. Documented feats in the sources include sealing interdimensional rifts (e.g., between the Microverse and Earth), defusing a nuclear missile, stopping genocidal plans, and combating powerful adversaries such as Baron Karza and, in later stories, foes like the Juggernaut. The Uni‑Power has manifested in ordinary people, established heroes, non-humans, twins, and infants, showing adaptability to varied physiologies. Because of its vast energy, the Uni‑Power has been actively sought or targeted by in‑universe organizations and figures (AIM, Psycho‑Man, Doctor Doom, S.H.I.E.L.D.).