Hiall,
this is my main character, the one that has finished the main game, and with whom I'd like to go on to all 3 DLCs.
My party was made of Cassie, Cole and Solas. With the hairy elf gone (
) I need a new mage, and I was opting for Dorian, as I'm a Knight Enchanter on my own.
Has anyone got a rock-solid build for this mage? I only went with fire and lightning so far, using the spec main ability when enemies get close. I left all the burden of cures and barriers to solas (or Dorian, eventually..)
I'm quite sure there must be a better point allocation for my char and maybe even a better company....
Anyone got good advices?
Thanksalot!
P.s. I romanced Josie.... if anyone cares... 
It's best to actually spec the entire party at once, so you can build synergies for combos.
As a KE you should take on the Barrier duty. Your Barrier should be better and you don't need it for yourself. Sticking it on Dorian deprives him of skill points he desperately needs in Pyro or Lightning.
I won't recommend my build since it was a special-purpose build: dragon fighting. I'm sure other people will post more general purpose builds, or you can search for one of the many already posted. KE is popular.
But for the Pyro part, definitely build down to Fire Mine and pick up Chaotic Focus as soon as possible after upgrading Fire Mine. You've got Barrier to burn and the damage buff is significant.