Compression is way off and maxing levels

Firstly, what mic is it? Is it, for instance, a mic with an attenuator position on the body, so you can limit the output at source? The reason I'm suggesting this is because it sounds very much as though he's overloading the mic preamp - and if that happens, then nothing at all you can do that will fix it - you've burned in permanent distortion, which is beyond the Laws of Physics to fix. So whatever happens, it's important to stop that.

Tip number two is actually going to work, whatever he does. You set up a second mic on a stand a good couple of feet away from him, and when he overloads the mic he's probably hanging on to, then you'll get an un-overloaded sound from the second one, if you've got it set appropriately - at that point, you just fix it in the mix. (Actually I hate saying that - it's always better to fix stuff at source, but this one may be an exception.)

If he cuts up rough about this, then get two or three pairs of old socks and put those over the mic. Might be worth doing that anyway, because if he's that loud, he's probably blasting the diaphragm anyway, and if you can prevent that, it's one less thing you have to fix later.

And actually, don't use compression. You have to bear in mind that Audition records dry anyway, and what you really want to do is keep this guy within the gamut. The best way to do this is to pay careful attention to him, and when he starts shouting, pull the mic fader back a bit. This is neither compression nor limiting really - it's a form of non-automatic gain control, and it's what most broadcast operators are rather good at. And it works...

So really it comes down to two things; stopping him overloading the mic, and then riding the levels to keep this within the bounds of being able to be listened to. And that's the thing; if he shouts and is then very quiet, nobody's going to listen to him for long anyway - so you're doing him a real favour here!