CrCo 30 Midden Heap of Charon (Base 5, +1 diameter, +1 touch, +2 group, +1 size 100 skeletons)
... create a tangled mass of the bones of 100 human skeletons, effectively hindering pursuers for a quick getaway.
Little bang for the buck, but stylish.
MarioJPC : no need to penetration, its only about creating mundane bone.
And yes, this is useless against magus.
It's the reason why i would have bought 100 mundane sword.
My skeletons can't touch and harm the opponent magus, because of parma and MR, but the swords...
Heyheyhey.
And i would not use a ritual if i were the magus casting.
If the troupe should say it's a ritual... okay but i would have to do better, like Erik suggested.
I could then do a Permanent Creo'd skeleton x 1000 individuals or maybe more (magnitude saved from the moon duration) and some Rego skeleton when needed.
But again, it's only a power, so ritual or not, i don't care. It's a "i want an army? i have!" power.
And that's i have done.
Thanks for the replies 
But with some Penetration (Casting total - Spell Level), that total is the Penetration for the skelleton's direct attacks, just like many spells that create temporally something or direct like trecherous spear. but si tru taht depend of the troupe.
The swords will touch the magus, but they wont do any damage, because the "power" of the attack is created via ReCo magic. Perhaps very, very sharp blades might cut the mage a bit, but no more damage.
Happily not in my troupe.
We rules that the movement his done by the corpse, but not touching your MR.
If a fireball blowns a mundane wall away, you are hit and take damage. We don't care that damage are done by magical exploding ball. The damage is mundane, and the movement mundane or magical doesn't bother
(And with Rego "aiming" no MR. If touching directly, not aiming, resisting.
It's why the corpse have to do attack rolls...
But with 100 skeletons around you, i would be sure you are hit hehehe)
Gotta admit, I see nothing "magical" about those swords, or that damage. No more than if a magical wind were to blow a boat that a mage was riding in - would the mage not move with the boat? If a magical wind were to blow the boat over a mage who was in the water, would the boat just "stop", because the wind cannot penetrate?
Mmmmm - maybe, but not in my sagas.
Or, if that doesn't seem the same to you, take these examples, all with a magically created skeleton, as the spell suggests:
- Skeleton pushes over a dead tree, which falls onto a mage.
- Skeleton throws a large branch of that dead tree at the mage.
- Skeleton hits the mage with that branch, as a club.
- Skeleton throws a javelin at the mage.
- Skeleton stabs the mage with that same javelin.
You can draw an arbitrary line, you can do whatever you want with your saga. Any of those can work, or not work... but to be consistent, it's all or nothing, and to say that none of those work is, imo, a stretch.
(Re?-)Read p 111, The Central Rule (at top). That's what people are talking about.
Base is 10 because animating a human corpse is level 10. So not Cr(Re)Co but Re(Cr)Co45.
Not a ritual yet.
jsut for say: its +3 moon 
I'm not sure if I'm being over fussy here, but I'd add a mentem requisite to give them the ability to follow new orders if issued.
(ReCo 10 + 1 Touch + 2 Group + 3 Moon + 2 Cr, Me Requsites)
This would only Create 10 Skeltons for Moon or 100 for Sun (or 1000 for Diameter for that ludicrously short and scary effect).
A
Well, that depends.
Does the rego spell simply allows you to give orders to a squeletton? If so, they need "intelligence".
Does it control the squeleton's movements? If so, they don't need it... But you won't be able to control much more than 1 at a time (I'd be generous and allow up to finesse squeletons)
Does that seems right ?
Rain of bones :
Creo Corpus (30)
Base 5, +2 Sun, +1 Touch, +2 Group
Create 10 corpses worth of bones.
Undead mercenaries :
Rego Corpus [Mentem] (35)
Base 10, +1 Concentration, +1 Touch, +2 Group, +1 Mentem requisite
You animate 10 skeletons and give them one simple order that they will follow as long as you concentrate.
For a spell, Me requisite would be useful it's true.
I'd say that creating 10 corpses at range touch is a stretch. You might want to increase it to voice range and level 35
On the other hand, your control spell should be fashionned after The Walking Corpse, with mentem being a casting requisite without additionnal magnitude required. OTOH, giving them a simple order at touch range? You can't touch them all at the casting time. So, voice range it is.
Undead mercenaries :
Rego Corpus [Mentem] (35)
Base 10, +1 Concentration, +2 Voice, +2 Group
You animate 10 skeletons and give them one simple order that they will follow as long as you concentrate.
You only need to have the range at casting, not after.
Of course, but how do you touch 10 skeletons at the same time?
I can't touch what don't exist. So i'm creating them. And in the same time Rego'd.
If i'd go with the 2spells solution, of course, the 2d would be voice. Or else both, because i avoid the requisite magnitudes ^^.
You have ten fingers, don't you? 
At touch range.
Suddenly, you've got 10 corpses that appear at touch range. Not 1 meter from you, not even 10cm, but at touch range. 10 corpses. Doesn't that seem ridiculous to you?
Better be Mr Fantastic then But then, that's why he's called this way.
Note, however, that I'd allow this.
for touch range you only have to be able to touch the nearest member of the target, in this case a group. Therefore the skeletons would appear all grouped together with only one of them touching you.
As for needing a Mentem req. Depends what you want them to do.
If you wanna stand there waving your arms dramatically as your skeletons murderise the enemy, no ME req is needed. If you want to tell your skeleton minions, "enter the manor house, kill everyone and bring me their bodies", you'd need a Me req.
You don't need to the range is the range from the caster to the nearest part of the target. There are several range touch target group spells in the core rules. Wizard's Autumn is a good example.