Serial Killer fights a Knight (But SCP fiction)

SCP-3000, Villains Wiki

Yaldabaoth (SCP Foundation)

SCP-096 VS SCP-055

SCP-2399 A Malfunctioning Destroyer (SCP Animation)

SCP-3999 vs Monika (DDLC) - Battles - Comic Vine

SCP-6659 - SCP Foundation

SCP-5000 - The Suitcase (SCP Animation)

SCP 682 VS The Immortal Snail (SCP Foundation VS Rooster Teeth) And So This is The End (Connections in comments) : r/DeathBattleMatchups

SCP-049, VS Battles Wiki

Who would win, Featherine (Umineko) vs SCP-3812 (SCP Foundation)? - Quora