Supreme demon king in a fictional world

Ren was an ordinary college student before he was killed, when he woke up he found himself in a body of a young boy with the same name. After a while realized he was in a world that had people from the anime, manga, novels, etc. he has read along with people he hasn't seen. Using the system he has received he tries to reach the pinnacle of strength.
Worlds
High school dxd
food wars
my dress up darling
maybe more series in the future