I've had this companion, Bez, for quite some time now. We first truly interacted when I was 14, 8 years ago. Initially, we met an agreement. I was an overly stressed, heavily bullied child, and was a breath away from stepping off the deep end.
Heads up...this is a long one...and there's no TL/DR here...
I asked, then when that didn't work, begged out to anything and anyone that would listen one night to just take control. I just didn't want to do it anymore, and the next step would have been...an unpleasant, and senselessly permanent solution. He answered, and instead of taking control, offered power, strength. I tried declining, and demanded it take control. His answer was: "I have to give before I can take."
He delivered. I've since grown much stronger with no effort. That is true to this day. I thought he was a demon, but I didn't care. I felt a rush of something. It was akin to anadrenalin rush crossed with anxiety and rage. He asked how much power I wanted, and I answered, enough to change things. That year, I started beating up bullies. However, he never took control, and life remained turbulent.
I could see him...draining others around me. For a long time, he was walking misfortune, and strife. I grew to loath and resent him, but couldn't be rid of him. I tried several times, and would always be positively overcome with terror. After a year, he was taxing those around me too much. I was tired of life, and of him. I took out my multitool one night, and jabbed into my arm where the biggest veins were. I got only one extremely thick crimson drip per, and an uproar of dismay and threats from him. I took out the nail file attatchment, pushed it into the puncture and pulled one vein out until I could see it. Then I ripped it. Another drip, and he seemed to darken the room around me, and terrified the hell out of me. I jabbed the blade into another large vessel that ran on the inside of my arm. I didn't know at the time that that was an artery, like I do now, but I cut in, and got really sleepy. I crawled into bed, terrified, but hoping I was done that night. Then I woke up the next morning with a bit of crusted blood over the veins, and a dried stream from where the artery was. I hid it, washed it, and wore longsleeves for a week.
I didn't see him again for another two years. When he returned, it was because I met a now-lost friend. He saw him. Said he saw a 'string' on me, and asked who the red guy was. I saw him then, and about died of fright. He had changed, became larger, but less...oppressive looking. The guy, Adlar, we'll call him, said he was powerful, but not a threat. He spoke little until I got deep into magic again, and began trying to get a better grip on wind magic and another type that worked by seizing possibilities and exerting aura to change the flow of events to a degree. He started offering advice, and halfway through freshman year, offered to help me 'filter' my magic. He said something about it was wrong, almost dirty. He explains now, that it was 'poisoned'. We worked together in a like manner for a long time.
Junior year, he began mentioning certain things he noticed in the world. He noted an imbalance of a sort. He remarked that he was watching 'scales tip slowly', and mentioned there were some parties at play. He doesn't want me elaborating more here, but to sum it up, he scared me, and I tried banishing him. I tried binding him first. My friend, Adlar, got me a quartz, and I made a necklace of it. He did something that 'will drain his powers into it', and it weakened him. Buuut...then the quartz started cracking from the inside. Then I tried banishing. I cut my hand with a knife I'd owned for a good while, coated a small iron orb in my blood, and threw it into a bonfire.
He was gone for a few days. He came back positively lamentful. He appologised, and said he would stop. I accepted, since I clearly can't get rid of him. Since then, we've been through a good bit, and even straightened out a few prior issues, but neither of us, we now realize, has any idea, what the hell he actually is.
That's where the question is, at long-last...what is he? I've given some background info, albeit abreviated and with some details spared...