Jornophelanthas just defend the elementalist very well, so I want to bring some infos about the thief.
The thief can be a one-target burster, very very deadly, but having trouble with large groups of foes. But you can also build him in order to be very effective against groups. I personnaly have a lvl80 thief specialize Condition Damage and Stealth and large groups are not a issue at all. Of course with such a build I’m not as effective as the first against solo foe.
So, in conclusion, you can have multiple builds of elementalist and multiples builds of thief which will completly change the gaming experience … So I just made your decision harder than it was, sorry :\.
) it will be something !