Novels like Nightmare Realm Summoner

All share GameLit

Rise of the Living Forge
4.53
Same author, also Mystery and Portal Fantasy / Isekai
Tales of the Endless Empire
4.12
Also Mystery and Anti-Hero Lead
Anathema
4.51
Also Mystery and Anti-Hero Lead
Heavy Metal
4.43
Also Mystery and Anti-Hero Lead
Dreamer's Throne
4.65
Also Mystery and Anti-Hero Lead
The Lone Wanderer: A World-hopping LitRPG Adventure
4.48
Also Mystery and Portal Fantasy / Isekai
The God of Death Just Wants to Quit?!
4.46
Also Anti-Hero Lead and Portal Fantasy / Isekai
Mask of Humanity
4.45
Also Anti-Hero Lead and Portal Fantasy / Isekai
Fantasy Realm - Infinite Worlds Adventure -
4.30
Also Anti-Hero Lead and Portal Fantasy / Isekai
Extra’s Mantle: Wait, What Do You Mean I Shouldn’t Exist?!
4.23
Also Anti-Hero Lead and Portal Fantasy / Isekai
The First Devil System
4.19
Also Anti-Hero Lead and Portal Fantasy / Isekai
Return of the Runebound Professor
4.59
Same author, also Portal Fantasy / Isekai and Strong Lead