Back Then, I Adored You - Chapter 76

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.

In 2040, The Earth was bathed in powerful radiation when a star went supernova, this radiation granted 50% of humans superhuman abilities but also created a nightmare for them as animals, insects, and carnivorous plants were mutated and became overpowered with intelligence, human started teetering on the brink of survival, a boy with no powers and no father, with a mother in a coma, seems destined for obscurity, but one night changed his life, with a new found hope to cure his mum from the everlasting sleep—Gene Elixir— he went on on a journey that would reshape his destiny...~Voracious Sovereign... Gene Devourer...Pray you won't be devoured by this power you wield which hunger is insatiable~~You call yourself an opportunist... But... you aren't free. A hungry man is not a free man...~

An RPG gamer who played the realistic VRMMORPG ‘The Amber Sword’ for years, finds himself teleported to a parallel world that resembled the game greatly. He takes on the body of an NPC who was fated to die, and with the feelings of the dying NPC and his own heartrending events in the game, he sets out to change the fate of a kingdom that was doomed to tragedy.

- Description from novelupdates