[QUOTE=Rhaevnn Xeno]@Dark Jack I know I'm probably assuming a lot here, but I figured if Morgan could learn how to filter soul ambiances, then, in theory, he should be able to also filter certain magic affects. Granted, he would be very poor at it, seeing that he would have to self teach himself, but if the shoe fits.[/QUOTE]
"Filter"... by which you would mean that he would be able to block out certain energy patterns? Eh, I'm sorry, but sniffers actually don't work that way. That's the reason so many sniffers end up losing themselves and turn numb: they are literally incapable of shutting out anything within range of their senses, and are uncontrollably bombarded with awareness of every bit of magical energy in their vicinity.
"Filtering" magical effects would be similarly improbable (borderline impossible). The only way to actually block out mind-affecting magic is with magic of one's own, which sniffers are inherently incapable of. The only way one could get away from mind-affecting magic without using magic oneself would be to simply shake it off and break it with one's will and intellect.

Yoshua... hmm... I've been pondering the properties of this spell for a while, and I think there are certain things I'd have to address, at least. The first one would be that the spell - or practically any mind-affecting spell of even basic potency - would ever linger in an area to continue to affect individuals within it over time. Rather, a mind-affecting spell would typically disperse its energy in an instant as it activated its effect, and then latch that energy onto anyone within the area of effect to specifically affect them, not the area around them. There are a lot of different reasons that this is the only way something like this would be practically doable, some very pseudo-scientific in relation to the universe and would take a while to explain, but the most fundamental reason is that the energy it would take to permeate an area with an effect of that magnitude would kill you. Not just the caster, though no ordinary mortal would be able to survive losing that much magical energy, but [I]everyone within the area of effect[/I]. The energy would have to be so immense that people would actually suffocate and die. (Spells that affect minds directly with any kind of reliability take [I]huge[/I] amounts of magical energy, much larger than spells of other types.)
If it did latch onto individuals and functioned by having the energy focus on those people, then the above issue would be dealt with. There is another thing about mind-affecting spells, though: the energy fed into casting the spell is depleted a lot faster if the target(s) try to resist the effect, and the stronger the will to resist the spell is in the target, the more energy will be required to even affect it at all. It would take an awareness of [I]what[/I] one was trying to resist to be able to do so, though. Simply knowing that one's mind was being affected by magic would not be enough to allow one to resist such a spell; one would have to be able to identify how one's mind was affected, in this case mainly by curbing aggression. If one knew this and did not want to be affected thusly, then additional energy would be drained in order to subdue the target's will, which would shorten its duration... or, if the spell proved insufficient to do so, simply render it ineffective.
So really, there'd be no guarantee that any kind of effect would linger at all, even a discomfort when performing aggressive actions. That said, an effect like this would probably be pretty hard to identify... one would probably notice that one was being manipulated, certainly, but recognizing how one's mind was being affected would be difficult, which would make resisting it similarly difficult.
For the same reason I imagine that anyone affected so strongly that they would not even stop someone trying to kill them would either have to simply not want to defend themselves, or be exceptionally susceptible to mind-affecting magic (an example of the latter would typically be very weak-minded individuals, such as often witnessed in late-stage piaan-addicts).