X-Men: Evolution (2000)

S1E3 Rogue Recruit

A young mutant girl, long unaware of her extraordinary powers, accidentally makes contact with a classmate, absorbing his abilities, memories, and essence. Overwhelmed and disoriented by the flood of unfamiliar experiences and emotions, she flees in distress, finding herself in the clutches of Mystique, who has her own plans. As she struggles to distinguish her identity from that of the boy she absorbed, her journey into the unknown begins.