Mercurio’s first journey to Earth put him at odds with the mighty Thor when he tried to steal the planet’s electromagnetic field in order to save his world, Garamos. Using a human host body, Mercurio had to siphon off energies from Dr. Donald Blake, whenever he transformed into the Thunder god, in order to change back to his natural alien appearance. However, Mercurio only succeeded in transforming himself into a half-negative being capable of performing new superhuman feats. He wanted to complete the transformation but was thwarted by Thor and the Warriors Three, and his body was sealed in molten iron.
That was not the end of the 4-D Man for he was soon teleported away from the Earth by Xorr the God-Jewel and returned to his home world. Mercurio had then attacked Xorr to steal his energies for the survival of Garamos, but encountered Thor while he was on a quest of his own. Searching for the missing Asgardians, Sif and Karnilla, Thor found them imprisoned within the God Jewel, so he allied himself with his former enemy and defeated Xorr. Mercurio collected the fragments that made up Xorr and returned to Garamos.
Mercurio had also come into contact with heroes such as Captain Marvel, Quasar and the Squadron Supreme. He has been held captive on the laboratory world of the Stranger and was most recently used as a pawn by Zarrko, the Tomorrow Man when he was pulled from the time stream to battle the newly formed Thor Corps.
The whereabouts of Mercurio, the 4-D Man, are currently unknown.