[2] While he was still just an infant, Magni's life was threatened by Balder's betrayal during the human resistance's raid led by Captain America.
However, that began to change when Magni met and befriended Jordahl, a mortal girl whom Thialfi had rescued upon arriving in the year 2170.
Magni was shocked and outraged at the Warriors Three's conduct as they began brutally murdering humans without even trying to find a peaceful solution.
Magni rushed to smother the blast of the bomber's explosive vest and succeeded, but the events he witnessed would trouble him greatly.
Afterwards Thialfi, who was already convinced that Thor and the Asgardians needed to leave Earth, confronted Magni and urged him to see the error of his father's ways.
Magni left Sif and returned to the royal palace, where he received word of Thialfi and Kya's failed assassination attempt on Thor.
He found himself able to pick the hammer up and, after learning to use it partly by instinct and partly under Sif's tutelage, he returned to the royal palace intending to test his father's purity of heart—if Thor could lift the hammer, Magni reasoned, his rule must be just and his actions righteous; if not, Magni considered that he may have to fight his father himself.
After a pitched battle in which Magni was critically injured and several other gods were killed, Thor found himself able to lift Mjolnir again thanks to his pure intentions to defend his family and undo the wrongs Loki had done.
While it appeared to be a ritual that would revive her son Iric, it actually brought Magni to Earth-616 as Thor learns about how he helped Enchantress father him in the other reality.
Magni accompanied Thor, Sif, and Enchantress in fighting Radioactive Man, King Cobra, Mister Hyde, and Grey Gargoyle.
His Asgardian physiology granted him great stamina, quick reflexes, an extremely long life span, and immunity to all Earthly diseases, toxins, and some magic.
As prince of New Asgard and a warrior in its service, Magni received training in the Asgardian arts of war granting him a high degree of proficiency in armed and unarmed combat.