Ia of the Omnitrix

He arrives on a meteorite, so that later Y/n finds him in a crater, the watch sticks to Y/n's left wrist, who decides to press the screen of the watch so that it then rises, showing the shadow of Heatblast

Omnitrix: takes out the lens that allows access to the Aliens catalog
Y/n: I choose Four Arms! presses the lens
Omnitrix: transforms the user into the alien chosen by the user, either to give peace or to fight.