I think this needs a free Rego requisite, to chuck the spears. The spears target an area, so anyone in the area has a chance of being hit. The recipient becomes the area of effect, the "T"arget is the metal created. This isn't like multiple casting, where each spell can be individually targeted for a recipient, IMO. If it were treated that way one could create spells similar to this (Pila of Fire) with T:Group and individually target the recipients, this becomes a far more effective way of multiple casting in this saga, or any saga, really. Add 2 magnitudes to a spell and target 10 opponents or 5 opponents 2 times, or some combination yielding a total of 10. Yes please, sign me up.
Also, in the same spirit of some authenticity or flair, let's try something more evocative of what the spell really does. I'm offering a suggestion below, but I'm not entirely happy with the name. The description which explains how Eve came across it, though, works with Eve's character.
Tomas's Invisible Pikemen Cr(Re)Te 30
R: Sight D: Mom T: Group
Invented by the reclusive Tomas, Eve found this lab text in the wreckage of his sanctum during her quest for gnostic secret knowledge. It was apparently overlooked or ignored by those who had been there before and looted the sanctum. Primarily useful against an angry mob without any magic resistance, Tomas used this spell to run away when the mobs came looking for him.
The spell creates 10 metal spears and throws them at a a designated general area. The spears fan out and have a chance of hitting anyone in that spot. It's a pretty good chance Dodge EF of X (9 maybe?), and some people may be hit more than once.
Base 5, +3 Sight, +2 Group, free rego requisite to throw the pikes.
Not entirely happy with it, it's trying to do some things that Ars isn't really good at doing...