Forged as a Celestial Guardian from the combined powers of his peers to confront the rogue Lanancuras, Mushra sacrificed his core to imprison the threat within a meteorite. This act stripped his immortality and memories, resulting in rebirth as a fire-wielding humanoid Enterran on the transformed world, Enterra.

Imprisoned near a waterfall after impersonating a king, he is encountered and freed by the human Yakumo. Recognizing her humanity yet moved by her compassion, he vows to protect her from hostile Enterrans seeking human extinction. He forms a traveling group with fellow Enterrans Sago and Kutal. Initially reckless and violent, he favors lethal force and destroys defeated foes' En-cards to prevent future threats, clashing with Yakumo's pacifism. This conflict leads to his temporary expulsion.

Following separation, he demonstrates growth by sparing the firefly Enterran Tombo and giving his En-card to Yakumo, acknowledging the cards' potential value. His combat abilities evolve: his base "Hyper Mushra" form wields flame attacks like "Hyper Burn" and "Inferno Blast." Enhanced by King Nipper, he gains wings and amplified powers as "Ultra Hyper Mushra," using techniques such as "Ultra Hyper Vortex Storm." Crucially, he fuses with Sago and Kutal via their En-cards to become the composite warrior Mushrambo, first triggered battling snake king Gyasa to rescue petrified allies. This fusion later achieves a "Golden Mushrambo" state against the corrupted Satan Mushrambo.

His bond with Yakumo deepens throughout their journey, intensifying his protective instincts. Confronting the dragon Ryuma, a black card corrupts Mushrambo into destruction, but Yakumo's emotional appeal purifies him, restoring his true form. After defeating Satan Mushrambo, the timeline resets, erasing the Human-Enterran war. In this new reality, the human child Binka rediscovers him; he regains his powers through jewels entrusted by Yakumo. The final battle against the freed Lanancuras reveals his celestial origin. After Lanancuras destroys Mushrambo's En-card and overpowers the heroes, Yakumo's residual energy revives the card, enabling Mushra to temporarily resume his true Celestial Guardian form. He defeats Lanancuras by carrying him into a solar flare, seemingly perishing, but fellow guardians later revive him, leading to reunion with Yakumo in Shinzo.

In the manga adaptation, his story diverges: he survives the conflict, marries Yakumo, fathers a daughter, and resides peacefully in a human-Enterran village.