Hellsing: a 700 year old vampire that is second only to Alucard. He also works for the Hellsing Organization and has similar powers to Alucard. He calls Seras by her real name and has 9 power restraints. He also likes to use assault rifles to fight ghouls and a blessed silver dagger to fight vampires.

Assassins Creed: an assassin from the 1940's sent to kill a templar taking the place of Adolf Hitler. He uses the classic hidden blades that all assassins have and also, he has a a Mauser pistol and a Zweihander sword. He has a considerable body count of templars and will not hesitate to use torture to get information.

Creepypasta: codenamed as "the Blitzkreig" thanks to the carnage he leaves behind. He doesn't wear a mask or anything that obstructs his face and has an unusually sane look in his eye. He shows a high amount of respect to his victims and doesn't particularly enjoy what he does. He goes about his killing with a mace and grenades., although his body count isn't that high, he is well known for the gore he leaves in his wake.

HTTYD: a traveler from the land of germany, prefers traveling alone or with a few friends. Has a Skrill as his dragon and has built up a high resistance to electric shocks. He is highly skilled in sword and ranged combat.

Stephen King multiverse: a being of the Macroverse and an adversary of Both It and the turtle that is Its' greatest enemy. Represents the balance between Order and Chaos. He always has to intervene in the battles between these two and is a direct guard of "the Other" which is essentially the creator of everything.

SAO: A top tier player of multiple VRMMO games. That's literally the best you can do in this anime.