Not much is known of Brom, except that he is a sorcerer, and does what he wants, which usually happens to be the logically unforeseeable*. He himself doesn't even know much of his past, a vague mystery early on and culminating with the magical student's stereotypical academic career, a time that prepares great minds by stroking ones inner hunger but never fully satisfying it.
What little he does know absolutely, and sticks to life as his informal mantra, is that when situations turn sour, it is best to listen to gut instinct and intuition. Now, this describes the common knuckle-head, but meat-shield knuckleheads don't commonly possess the flexibility of word-casting and random magic, along with the brazenfaced perspicacity to unleash them at a moment's notice, which has led to the perception of Brom as a trigger-happy and slightly mad sorcerer.
This is a perception his closest friends, colleagues, and the world at large, are slowly coming around to, which he doesn't know what to think about. But, no matter what, Brom is going to prove to everyone either his worth or to fear him (he is sorting out which he'd prefer more) on his quests in search of purpose and power.
Word-casting, a variety of elemental as well as mundane, flexible attacks.
His story starts where his academic career ended, and is telling. On what was to be his senior undergrad year, he was bitten by a vampire, and also accidentally unleashed a deadly gelatinous cube in his academy's basement. Rather than reacting normally, his giddiness at his life finally starting to take off with becoming a magical creature of the night, in keeping his secret he forgot to tell anyone of the deadly cube now silently drifting around, and consequently a number of future errand-running students met their untimely ends.
Carrying the remains' of the students with him everywhere, no one still believes he is trying very hard to be a a responsible and noble creature of the night, a cat, which he became at a future point, which is another story altogether.