Base ReCo10: Control a targets motions, +2 Voice, +3 sun
Don't beat yourself up (ReCo25)
The target hits their head against the nearest hard object until the sun sets/rises. Unconciousness does not end the effect, because the body (not the mind) is controlled.
Wipe your brains of the floor (ReCo30)
As before (+1 fancy effect), but the target wipes the floor after his brain has been dashed out.
There should probably be a lot more extra magnitudes for "fancy effect" here as with both of these spells there's an effect that would normally require the mage's concentration.
Your first spell would work OK as a ReMe - a person whose mind is controlled to whack his head against a wall will go and do it in the most expeditious way possible - but as a ReCo, the spell actually has to be able to point the target in the direction of a hard object and move him there before he can start whacking. Spells, as a rule, don't think, so without a mage's concentration, there has to be some formula to find a hard object and start whacking. This might even require Intellego and Terram requisites. I'd add at least three levels of magnitude.
As for the second, you now have a spell which does the following list of things:
forces a body to walk to a hard object - the spell has to find this object
forces the body to dash its brains out against the object - this part is pretty easy as ReCo
figures out when the brains are dashed out - Intellego Corpus?
at that point, forces the dead body to clean up its own brain matter, once again a complex operation and, in fact, since the body is dead and not using any of its own senses, requires further Intellego to locate the pool of brain matter and collect it effectively.
This second spell should probably be somewhere at the Ritual level.
I don't think so. The spell is pretty simple and straight forward. It induces a repetative bodily action. The magus may have to concentrate to start it up, but once in flow, it can go by itself. No need for the requisites, no need for additional magnitudes, absolutely no need for a ritual.
If this was "stop hitting yourself," the spell, where someone just punches himself in the head, there'd be no argument. But that point where you have to go out and find an object to hit one's self against - that's tricky.
There's autonomy in there, and either you start stacking on requisites or you start putting in the autonomy through the same levels of effect you'd use to raise the dead; you need the spell to perform multiple independent actions.
But, even if a spell has 13 requisites, it still only increases a single magnitude. And I say you just point the guy at the wall and let him loose. Mopping up afterwards, well, that may need supervision
Make them kneel and hit the ground with their faces over and over again. Problem solved.
It should allow for natural resistance spells, though, since the dude is aware of what you are making him do and would want to resist. After he falls inconscious from hiting his head against the ground this stops being a problem, but until he falls unconscious he can try to prevent such effect
As long as the mage is aware of a "convenient hard object" at the time of casting, no requisite or added complexity should be required (at least for the beat your head against this "convenient hard object" until you are dead spell). You are already controlling the targets movement...
If the "convenient hard object" is not very close by, complete control of the target body would be required to get it there, so this might raise the magnitude a bit.
Now, if you wanted your target to go off and find a nice hard object for some reason (e.g. there isn't one conveniently available), then it would require at least an intellego requisite or it wouldn't work.
The whole "now clean up the mess you made" part is another story. It is clearly a new effect (especially assuming that you want the new corpse to stop beating it's head against the aforementioned hard object before starting to clean up). Tying them together requires some increase in complexity. How much of an increase depends on how tidy you want the floor (or whatever) to be when done. "Hmmm... did I get every little bit of my brain or should I keep sponging?"...
The whole package would be fairly high in magnitude (assuming concentration isn't required), but I don't think it would quite reach ritual level.
On the other hand, one use of this spell in public should ensure that nobody messes with the scary mages... or send everyone looking for their torches and pitchforks, one or the other!
I never intended it as a "serious" attack spell anyway. Anything higher than lvl 10 has penetration problems with the big bad guy's magical resistance.
I also never thought of the target walking around with Moh's scale of mineral hardness. I also believe that banging your head against any kind of ground that is hard enough to stand on for a prolonged period of time should cause significant damage. I am scientifically-minded person though: Feel free to prove the opposite (please ask your best friend to film it for YouTube).
About the additional effect: It doesn't by itself unbalance the game, but it drives home the point that ReCo spells don't stop when you die.
There are other ideas I have concerning ReCo anyway:
I love the touch of the Oaf spell (Lvl3) from the wiki. I wonder how much it would cost to make sb stick out his tongue at somebody else.
I also wonder about a diameter version of "Lifting the dangling puppet" (Please clear the area. It's raining men (Halleluja!)