need help .. no more respecs

I used to run pure

Hydra as my go-to for new ladder seasons, simply because it can handle everything by itself in a fairly chill and safe but still speedy manner. And can later proceed to easily farm most things worth farming early on.

For your full play through though, you will encounter some immunes that you'll need to babysit your merc for while he takes them down (getting him geared is really the priority). But that's true for pretty much every sorc build, especially single-element.

That "wall" won't disappear until you get a sunder charm for your (main) element which, if you're on RotW, won't happen until you start clearing TZs and heralds, along with some -res to make real use of it.