SPN: Being immortal he became one of the best demonologists to ever walk the earth. Able to drop devils and even archangels as well he is a hunter with a lot to offer and a lot to give to people wanting to do right.
Modern day: Alexander became a priest that helps banish demons from hosts as well as kill destructive forces of the demonic and angelic world. He is talented and dangerous and demons all kind fear him because he can slay a devil with not a problem.
Sherlock: Being in the world of the great brilliant mind Sherlock Alexander helps with the supernatural cases ending up having to help with the Baskerville hounds case as well. But even then his talents didn't go unnoticed by Sherlock as he was able to summon and control demons as well as angels.
Olden days of the Crusaders : A fighter and obeyed the orders of god with no hesitation. But such obideance isn't always seen as he soon turns to dark arts and demons to destory villages in gods name. But as he does so his ind becomes a darker place and one that even devils dare not enter. But is there any hope for this Crusader?