Short version:
The journey of a silver-haired, expressionless (or so she seems) girl through the worlds of A Certain Magical Index and Date A Live (mainly Date A Live), seeking her past and her powers, and doing what she can without regrets.
Long version:
Always lost, always failing.
Salvation? Slaughter.
Reason? Emotion.
Wrong? Right.
So many things in this world contradict each other.
Luckily, she can see her own path clearly.
All that matters is having no regrets.
No matter how it ends.
A single heroine story.
Main worlds: A Certain Magical Index and Date A Live.
Although the protagonist is technically at the highest level, this is not a conventional invincible power fantasy.
Note: This story has the nature of an Impure World Reincarnation.