For me magika is not such a problem, casting time of dark flare is. With animation cut and stuffs, I'm around 600 dps max with this build and I use daedric spear to add more dps.Dark Flare (does good damage and adds 50 spell power to next attack)
Spell Symmetry (Might of the Guild passive, 10% spell power for next magical attack)
Vampire's Bane (spam a few times then repeat)
As your getting mana back with Spell Symmetry, you can cast endlessly (as the healer will be spamming area heals anyway) you can keep up 800dps (if you are using spell damage jewelry, full light set and about 50% spell crit)
First boss of AA trial is not so much relevant since you can cast your nova, and the fight duration is less than 20 sec. It artificially raises your dps on short fights.Crushing Shock + Light Attack with Vampire's Bane. Evil Hunter in AA (first 3 bosses). Potion, food ofc. 1000+ at first AA golem. Less and less at next bosses.