"Demons come in many forms, as they are capable of appearing as anything, even angels themselves. However, demons are manipulative and evil, never attempt to summon one into your world or it will end terribly." - Excerpt from Of Men and Demons

...

"My name is Melvin and I own one of the world's leading research institutes. I summoned your lordship so I can avenge my children." Melvin said as he shakily got to his feet.

"Why is someone as wealthy as you relying on demons? Surely you can find human assassins, can you not?" Oliver asked while he inspected the old man.

A wrinkled face, however his eyes were cold and his clothes spotless despite him having just been on the floor.

All in all, he looked like a strict well dressed grandpa. Melvin clenched his fists as he explained to Oliver.

"Because my children deaths are public, I can't hire anyone to kill the culprits without it blowing back on me." Melvin stared at the floating ball of darkness and felt a bit proud of himself.

"So you want a death that looks like an accident or something?" Oliver was but a librarian in his previous life, how could he go kill people?

'Shit! Is there a way to go back to Hell? I'm not an assassin or even a demon. Why not we just wait for the police to arrest them?'

Of course, Oliver didn't say it aloud, instead he turned his attention from Melvin to the bodies in the corner.

"I used them as offerings to open a Gate of Hell. I don't know if you can use them, however I saved them just in case." Melvin said as he walked over to a wooden chair and sat down.

'Somethings telling me that I can use these bodies to strengthen myself, but I'll need to devour at least fifty bodies to reach the Second Heirarchy.'

The ranks of demons followed a strict system, made by the Absolutes who ruled over Hell.

Third Hierarchy(Demon Spawns)

Second Hierarchy(Bloodline Awakening)

First Hierarchy(Higher Demons)

Demon Lord

Many demons wouldn't even be able to make it to the Demon Lord rank due to the sheer difficulty in rising through ranks.

Oliver had yet to even awaken a bloodline, so he was currently at the Third Hierarchy. Despite being weak in demon terms, he possessed enough strength to fight against ten men easily.

"I don't want them to die a quick death! I want them to know that I, Melvin Holt, have avenged my children." 

"How did your children die? You seem to carry a lot of hatred towards the culprits." Oliver noted and Melvin nodded sadly.

"They were tortured before they died, and my daughter was raped and then killed. All because of me. If I didn't decide to send them away, maybe they'd still be alive..." 

"Oh. That sucks. If you can find more bodies, dealing with them wouldn't be a big problem." Oliver knew it wouldn't be hard to get more bodies since he knew Melvin really wanted his revenge.

"I can see what I'll do." Melvin bowed and then walked to the end of the room and pushed the door open and left.

Melvin wasn't worried Oliver would run away, in fact, it didn't even cross his mind. Why would a demon run away from a task they wished to complete?