sssd will clear out the absolute fuck out of everything with sparks in melee range and fireballs at distance, both spells being insanely mana-cost-effective if used correctly.
Why do people *always* dismiss the issue of damage-time-effectiveness? This is arguably much more important than mana-cost-effectiveness, especially if facing hard-hitting opponents who you want to dispose of ASAP. In those cases Shrapmetal is love, Shrapmetal is life.
In fact, going light is stronger than going dake here - you already have all the magical offensive power you need, and light gives you the insane defense that your spellcasters normally lack.
Well, fair enough. But the light path is ewww.
May I introduce you to the concept of recovery time?
Which sparks, being a low-level spell, has very, VERY little of.
Then there's such thing as hit recovery, which enemies also have.
When you combine very fast spell with a lot of projectiles that deal tons of damage, from at least 3 casters, on auto cast, what you get is near-perma-stunned mobs (the ones that survive for longer than a second, anyway).