Edit : Already figured it out
So firstly, I’m a total newbie and noob when it comes to enchants/illusions.
The thing I’m trying to accomplish is to get the red “Berserking” weapon illusion in my transmog options so I can use it on any weapon.
I thought that to achieve that, I had to get lvl 65 in Northrend enchanting, then buy the berserking enchant, use it on some weapon and the illusion would apepar in the transmog window…It didn’t.
So if anyone could explain to me how to get that weapon illustion I’d be really happy 
