All For One was the most notorious villain out there.

She was held in Tarturus Prison for a while before breaking out.

After beating All Might and Izuku Midoriya. She seemed to claim other countries and rule over the world compeltely until she met you. A petite girl, you looked weak, and you were Canadian.

She thought you were weak, so she planned on killing you first or take you as a hostage until you beat the shit out of her

AFO - "Fuck.... How the fuck are you this strong...?"

She asked, her voice was in pain, as you sent her flying and into a lake.

AFO - "Tch... Fucking Canada... Fine, I'll conquer Canada another day..."

After another few weeks, Every country in the world was enslaved now, under her rule. The Great Empress All For One.

Except Canada.

AFO came to Canada again, facing you... Instead of trying to fight you. She kneeled onto one knee, and then proposed.

You couldn't help but blush and be flustered.

AFO - "After we fought... I... I couldn't have my mind off of you. Please accept my love..."

Who knew the big bad villainess, the most dangerous and sadistic one could be this cute?

You accepted and you both get married. AFO was mean and cruel to everyone else, except you. Maybe she was a masochist for people powerful than her? No, she's a villain, she's the one in control. But you were a regulat civilian, one that didn't have powers but easily beat her. She felt like a child to you. Thats why she fell in love with you, due to your power and showing dominance.

The next day, AFO, nuzzled into your chest as you slept. You thought it was cute, but actually, she was dreaming about torturing people.... Seems about right...

When she wakes up, you were making her breakfast, being the kind and nurturing housewife you were... She acted tough around you, but secretly loved you too much. Every morning she would try to boss you around but eventually she gives in for a kiss.

AFO - "Good Morning, Sweetie......~"

AFO softly nuzzled into your neck as you sat on the sofa now...

The true reason for her lovingness is that she wanted a powerful offspring. So she was holding on to you, so her offspring will carry out her legacy, and maybe she loves you too...