Summoning Goes Wrong

Welcome, prospective summoners...

I entered the room and a chill ran down my spine. Even though everything had been prepared, something still felt... off... As if an unseen force was warning me that this was a bad idea. But I'd been preparing this for a long time, and a cold room wouldn't deter me. I started to draw the pentacle on the ground, using an unknown red fluid that someone had given me. It could be anything, animal blood, red paint, ketchup, or god forbid, human blood. I shivered again as I finished the 5-pointed star and began to finish the circle. My heart pounded in my chest as every second got me closer to my goal. This is what I had been preparing for, for who knew how long, and my time was almost here.

The final preparations were done, and I stepped back to look over my work one last time. Once I started, there was no going back. And if I fucked up... Goosebumps ran up my arms as I envisioned what would happen to me and I shuddered at the thought of something going wrong. If I fucked up, unspeakable things would happen to me, and death would be considered a mercy.

Now.

What am I summoning?