Shiradi's Standard procs are:
- 7% for 10d10 Sonic damage;
- 7% for 2d100 Force damage;
- 7% for 1d100 Random damage;
- 7% for Uknown Effect from unknown list.
On average for an Air Savant spec with 7/6/6 on main element, 7/1/1 on Force and Fire these procs have the following average per projectile (consider Twilight with combustion, EE Iron Beads and Planar focus of Erudition):
- ~18 Sonic damage;
- ~47 Force damage;
- ~29 Random damage;
- ... average Uknown for the Double Rainbow list.
An example of these calculation is the following Sonic proc:=((10*5.5)*(435)/100*9%*225%+(10*5.5)*(435)/100*(1-9%))*0.07where 435 is the sonic spellpower factoring Maximize and Empower feats with a 80 item potency from staff.
Now adding once all the procs to a Chain Lightning of 25d6 dices and five times to a Magic Missile for the above said build we get:
- ~1196 average damage per cast for Chain Lightning;
- ~648 average damage per cast of Magic Missile.
Now if we compare the mana amount spent for point of damage with these numbers we get that:
- Chain Lightning does 18.4 points of damage per spellpoint (without heighten) with Maximize and Empower;
- Magic Missile does 14.7 points of damage per spellpoint with Maximize and Empower.
You get even better results if you consider a Polar Ray which does more damage and costs even less spellpoints.
Conclusion:
What i want to say is that waiting for your Missiles spells to spam damage over time effects it is efficient but it's not the faster way to clean up trash. You get better results with higher mana consuming spells. I reserve these Missiles spells for longer fights, that's all.
EDIT:
As said below, I usually consider 95% chance to land a reflex save spell, in this case Chain Lightning (which is mostly not true for EE). On the other hand the example above can be done with Polar Ray which doesn't allow reflex save, does more damage and costs less mana (though it's single-target).