 Previous encounters with people he thought to be fellow Kryptonians, Power Girl (who is, in fact from the Krypton of the Earth-Two universe) and Mon-El, have led to disappointment.The arrival of Supergirl, who has been confirmed to be not only from Krypton, but also his cousin, has relieved this loneliness somewhat.Superman's Fortress of Solitude acts as a place of solace for him in times of loneliness and despair.