lol, if the rouge has a stealth llv 3 or more, mage has no chance, in my case, i play with VERY low ping (54) if i click gouge, it'll work almost instantaniously, same with the rest of my skills.
Mages are easily killed, simply approach during stealth, use merci then a quick gouge+attack combo so you get a cheap shot in at the same time gouge works, this will eliminate the chance of getting shackled by them..make sure gouge is atleast two though, so when it finishes, stealth will almost be ready, auto attack 2 times and stealth will be done so do merci attack etc till gouge is back, you'll take dmg thought but eh. Easy kills .
Strategie is all thats needed