(Crossover) I'm Not Helping the Wicked

My name is Wagatsuma Izumi. I have an exceptionally strong memory and can recall everything from my childhood. I was born with emotional detachment. Nothing matters to me. I don't like to talk or smile, and my parents often argue because of it. Even when my mother locked my sister and me in a cage because my father was busy with work, I simply watched indifferently, unmoved by it all.

Heaven has robbed me of my emotions, but that doesn't make me sad. Someone who called themself a System said they wanted to play a game with me. If I traveled to different worlds and did ten good deeds in each one, they would make me normal again.

I don't really care whether I become normal, but sometimes I am curious about human emotions and behavior. I thought this System must have read my research journal on human behavior. Otherwise, why would it make such an appealing offer? And so my journey to other worlds began...

In other worlds, I helped a liquor company test counterfeit liquor, helped a cursed spirit seal away a blindfolded villain, helped a bandage-wearing guy figure out why his suicide attempts failed, helped a pink-haired robot cat cure someone's inability to speak, helped Tomie get rid of Tomie, went abroad to cook for Hannibal, helped conduct research at a Hydra base, helped the Joker achieve his dream of comedy, and helped Death Eaters purge the impure-blooded. I also went to ancient China to help Lady Daji put down a rebellion, help the Queen of the Women's Kingdom find a husband, and help the Red Shoes grow their organization. I sincerely meant to help, but later every organization went under, and the people I helped all met their ends. Everyone said I was a spy.

Now I'm better, and my legend is told everywhere. Then the worlds merged.

The protagonist's original world is Future Diary. Feel free to suggest other things you'd like to see. The above isn't an exhaustive list.

Premise: What is fate? It's yourself!