Assuming All day long buffs are on, though If I really need to I could time stop on the ones I need for the fight.
Quickened Greater Dispel magic Over an area to counter his spell.
Not Sure how many people failed to save, so I'll just roll for 5, assuming that many make the save.
Spoiler
Show
(1d20+33)[48]
(1d20+33)[51]
(1d20+33)[43]
(1d20+33)[49]
(1d20+33)[42]
Anything 11 above the Drows CL is a success.
Using Improv to boost the Checks, up to three more beyond the 5 will be Boosted, and any number less than 5 gives me improv points back. (as I couldn't have spent them.)
Then using fully expending a single blast rod for 120 damage (thank you maximize), and the most + to hit improvisation can give me (13) .
(1d20+37)[54] Damage 120 Touch Attack
Improvisation now at [43/108] points.
Finally, The cognition cores will either cast spell immunity to negate the mage's next spell should they identify it (
(1d20+67)[81] spellcraft), or will Use and then dismiss an antimagic field to stop the spell from hitting Vitis (unless the spell is identified as being of no danger to me).
Also, Time stop Dimension door trickery for safe landing,