The Cards, the Cards, the Cards will tell,
The Past, The Present and the Future as well.
Some powerful being had decided to create enchanted Trading Cards. Each one containing a sexy picture of a superpowerful individual. It attracts the attention of a fellow superpowerful character or someone around a superpowerful person. Once picked up by them, the spell triggers.
They gain the powers of being pictured in the card, with perhaps a little bonus in exchange for the other effect. For while they gain those abilities, they also gain elements of the personality of the character. It had sexual effects. Like enhanced libido, added fetishes, bisexuality, and/or other kinks.
And so the magical cards were sprinked through reality, till one of them landed and was found by...