I don't know if anyone started a similar topic already as I don't log-in very often.
Have you considered this? Counting Kristoff, Anders, Wynne now there are quite a few characters that have been possessed by a spirit for a reason or another.
As the Inquisitor is the only survivor from the explosion that caused a breach to the Fade... is it possible that He/She has been possessed by a spirit in his/her last moments and so saved by death? Still can't figure if eventually the spirit had a specific purpose itself by taking a mortal body...
This would also explain why he/she is able to interfere with breaches, at least so it seems from the last trailer... and of course use that "green magic" even is he/she is a warrior/rogue...
Speculations... what is your opinion guys?
I haven't read any background on the Inquisitor, so I can't really be sure.
There's differences between the amount of possession, too. There's Kristoff, who wasn't even possessed, so much as his body being used as a husk to sustain Justice. Then Anders, who doesn't have complete control over his body. Then, of course, there is Wynne and Evangeline, who have complete control over their bodies. There are differences between Wynne and Evangeline and Anders and Kristoff. Kristoff was dead and Justice needed a place to go. Justice needed a place to go, and Anders was alive and had no physical need for a spirit. In both those cases, Justice had control, obviously more in the case of Kristoff. Then there is Wynne and Evangline, who, even in their cases, are different. Wynne was on the verge of death and took the aid of a spirit, and Evangeline was literally dead. Wynne was always "close" to spirits, for lack of a better word, and she was a mage. The Baroness brought everyone out of the Fade, which ended up making Justice possess Kristoff, and Anders knew Justice and let him in. Kristoff is a weird case, and Wynne and Anders were both mages in contact with a spirit. Evangeline just got lucky because Wynne was there.
Point of my long and kind of irrelevant rant being that everyone who was possessed was in direct contact with a spirit via the Fade, and magic was necessary in order for that contact to occur. While it is possible for anyone who is not a dwarf to be possessed, it is far more likely for a mage to get possessed instead of a non-mage. In the case of a demon, they would go after the stronger target to possess, and spirits don't really care about mortals. Anders personally knew a spirit and allowed him to enter, and Wynne always had a strong connection with spirits and was offered aid in her dying hour. I find it unlikely that a spirit would go up to the Inquisitor and offer aid, especially if the Inquisitor isn't a mage.
I think it's just a case of the Sole Survivor. You know, like in Mass Effect.