I remember a few fics but I can't remember their names

1) Harry is in Azkaban. When they come to free him he can't remember anything. He hates Dumbledore and he kills Bellatrix.

2) Harry runs away after the final battle. Years later he is found. He starts the Death Eaters again and takes over the ministry. He kills Neville infront of everyone in the great hall.

3) Harry is in the future. He is a squib and is married. He cheats on his wife with Tonks and Daphne. Neville and Hermione hate him.

 

The third one is Lost Time by Amerision

The first two are quite generic as concepts might want to add more details.