Mistress Love is an abstract being who is the cosmic embodiment of love itself. How she came to be and her true origins are shrouded in mystery.
She first appeared to the asgardian known as the Enchantress who was seeking true love. However in order to deem Amora worthy of her gifts Love tested her which pitted the Enchantress against the Defenders. Having failed the test, Love abandoned the Enchantress and returned to the cosmos.
Sometime later when Thanos of Titan had the Infinity Gauntlet in his possession Love, and Master Hate were among several other cosmic entities who wished to remove the power from Thanos. During the battle that followed both Master Hate and Mistress Love were turned to statues alongside the other cosmic entities. However after Nebula gained control of the glove, Love and the other entities again fought and were once again defeated. However once Adam Warlock managed to wrest control of the glove from Nebula they were returned to normal once more. Again Love and Master Hate attended a hearing presented by Eternity and the Living Tribunal and other cosmic beings to decide whether Adam should continue to have the gauntlet or to take it away from him. The Tribunal decided to instead to spread the Infinity Gems to others. After the hearing ended Love and her counter-part Master Hate left.
Later a girl had fallen in love with the Silver Surfer and Love appeared to her. Sympathetic to her plea Love turned her into Avatar, an avatar of love. However Loves opposite Master Hate was watching and offered Avatar additional strength. She accepted and became even more powerful. She confronted the Silver Surfer and was eventually defeated by him.
Later still Thanos again gained immense power when he gained control of the Heart of the Infinite and was confronted by Love, Hate, and other cosmic entities. However due to his immense power she along with the other cosmic entities were easily defeated. Thanos destroyed the universe, but then had a change of heart and recreated it and everyone in it. Love and the other cosmic entities were among those who where recreated.
Mistress Loves current whereabouts are unknown.