No Regrets
When Mavis first met him, she was, well, intrigued.
There was something mysterious about the Black Wizard and also, something else.
Sadness.
A deep despair that seemed to come off him. Mavis always wished to erase it.
As he told her of his curse, Mavis used her illusion magic to summon forth visions of animals that could not be killed.
And for the first time, he smiled. And thanked her.
He helped them all, teaching them how to use magic. Because of this, Mavis was able to come up with her strategy, defeat Blue Skull and free Magnolia.
When Yury was possessed, she used the spell he taught her: Law. After using it, Mavis was able to subdue Yury. However, she had to pay the ultimate price: becoming immortal. And thus, she fell under the same curse.
However, Mavis had no regrets. She was able to save her nakama, and that was all that mattered.
They met again, ten years later, and Mavis found out that he was actually Zeref, the Black Wizard. She didn't care, however as she hugged him out of joy, thanking him for his help earlier.
When Zeref commented that she hasn't changed at all, Mavis told him that she had gained a body that stopped ageing.
Zeref was surprised and inspected her. And then told Mavis the horrible truth.
She was now cursed, just like him. And when she learnt the true meaning of life, she would start killing those around her.
Mavis didn't want to believe it, and ran away.
Days later, Yury became a father. His son was named by Mavis, who called him Makarov.
Mavis leaned over to grasp Rita's hand.
The effect was immediate. Rita's life force started to drain away.
Shocked and horrified at what she had done, Mavis rushed out of the guild.
Almost a year passed. Mavis kept to herself, living in the forest, slowly killing everything around her. She even stopped eating, in hopes that she would die and have this suffering done with.
Zeref came across her once more. Sick and tired of her aimless life, Mavis tearfully begged him to kill her. But Zeref shook his head, saying there was nothing he could do.
He started to talk about what he was trying to do to end his life. Rambling on and on, he finally told her that he lived to die.
And there seemed to be no purpose for his life.
Mavis sprung forth and clasped her slender arms around his neck, pulling him into a tight embrace. She whispered words of acceptance and begged him not to give up, they would find a cure for the curse, together.
She knew they would.
Zeref broke down, as he told her that she was the only person who had ever spoken so kindly to him, who had ever accepted him.
And she was the only person, he had loved this much.
Mavis closed her eyes, as he cupped her face in his hands and moved closer to her. Time itself seemed to stop, as his lips descended upon hers.
As they pulled away, Mavis felt her life start to drain from her. Even though she was immortal, Zeref had somehow killed her, with his love.
Mavis smiled shakily at Zeref. 'It's okay...' was what she wanted to whisper as tears of sorrow and guilt rolled down his cheeks.
Because, she had no regrets.