One of my players wants to be able to manipulate swords and other weapons and be able to use them on enemies up to voice range. i.e He wants to use a rego terram to pick up a sword, and under 2 minutes be able to levitate this sword to attack an enemy.
I am thinking of the following:
Base: 3 Control or Move Dirt in a very unnatural Fashion
Range: Voice (+2)
Duration: Diameter (+1)
Target: Group (+2)
But still, with what skill will he be able to do this, what will the swords attack rating be? Is it his per+finesse?
What he want to do is to animate a bunch of swords, then control them to attack his foes, while he at the same time attack another enemy. Is this possible?
If so, how...? Do I need to add +2 to +3 magnitudes to give him a control and how will the swords know whom to attack? Do I have to add an Intelligo requisite in order for the swords to be able to distinguish who to attack and who not to attack?
Well, your choice of base guideline and RDT parameters are fine, but you need to add two magnitudes to affect metal with Rego/Terram so your spell is: Base 3, +2 Voice, +1 Diameter, +2 Group, +2 Metal = 30.
One potential problem with such a spell, however, is that you'll need to work out a set of combat stats for the swords' attack rolls. As for the rest of your questions, if the caster is on hand when the spell is performed, I'd say the direction given to the swords is unambiguous on the intended target though I suppose if grogs were engaged in melee at the same time there might be issues in such a situation, however, maybe the swords could be used to cover their retreat?
I'm not an expert, but here's what I'd offer:
A) You'll need to make concentration checks to keep the swords attacking under your command while doing anything else; unless you make them intelligent. I'd say per+finesse is reasonable for their attack rolls while controlling them.
B) Base 3. +2 mags for metal.
Range: Voice (+2)
Duration: Diameter (+1)
Target: Ind
That's level 20 for a baseline control of one sword.
Now, if you want to give the sword intelligence (akin to The Treacherous Spear, ReHe25) I'd add a Muto requisite (for +1 magnitude to give the sword the capacity for self-control that is natural to all living things) and possibly +1 for complexity (being able to specify who to attack), for a total of either 25 or 30 for one sword; 35 or 40 for a group.
If you're using the enemies weapons against them, I'd say The Treacherous Spear has the rules just fine (although metal weapons might be harder to destroy). If you're not, I'd go with Per+Finesse for attack rolls and adding Pre to damage (because combat magi don't use presence enough :p)
as far as using finesse to attack with I would steal inspiration from the craft magic rules in Covenants. Doing something with Rego and finesse is a dificulty of at least three higher than doing it with a person and the relevant skill. I 'd use attack totals of Per + finesse + weapon bonus -3 for a single sword and with a larger penalty for target group spell (but I'd certainly give the group of swords a trained group bonus that might well be more than enough to offset the larger penalty for doing it with finesse rather than the real skill).
concentration instead of leadership - since the entire 'squad' is effectively the magus
weapon skill (for trained group bonus calculation and weapon stat calculation) would be finesse -3. Per replaces Dex, but Qik is caster's Qik
an extra botch die for each weapon in a group, including the first.
And finally...
Rego magic directly controlling the sword(s) - they will have to penetrate magic resistance.
As for the whole concentration thing, I wouldn't be over bothered and would just let the swords/weapons follow the caster's simple requests. If the spell itself is not concentration duration, then the caster can give them orders and leave them be. They will need additional orders once their orders are completed or invalidated.
Spells like 'Awaken the Slumbering Corpse' or 'The Treacherous Spear' come to mind: these don't have any special additional anything to allow them to act without direct caster input.
