The past history of Loki of Earth-774 mirrors that of his Earth-616 counterpart until shortly after Bruce Banner was transformed into the Hulk. In this reality, the Hulk retained Bruce Banner's mind when transformed. Much like his Earth-616 counterpart at the time, he sought to use the Hulk as a pawn against his step-brother Thor. To this end he would create the illusion of bundle of TNT on a railroad track that would entire Banner to try and stop it from exploding.
Banner would realize that the TNT was an illusion and bound away before an oncoming train could collide with him, foiling Loki's plot. This change in events would prevent the circumstances that led to the formation of the Avengers from ever happening.
Seemingly those of Loki Laufeyson (Earth-616)#Powers.