Spell crafting : Blessing of the blossom head

My wife plays a Maga from Merinita who is a big nature fan. As an Herbam specialist she imagines ways to harm or kill with plant-themed spells.

Hence the Blessing of the blossom head :
CrHe 20 (Corpus requisite)
R. Voice, D. Diameter, T. Individual

A small plant grows on the targeted human’s head. The roots are ravaging her flesh for the duration of the spell, causing great torment. A DEX+Finesse Check may be required if the target is moving. The targeted character may try to unroot the plant each round with DEX + Athletics Check vs. a difficulty of 6. If she fails, she suffers a medium wound. At the end of the duration, the plant vanishes but the wounds and pain stay. It may not be a blessing after all. For Kerridwen of Merinita the growing plant is a small mint sprout.

(Base 1 create a living plant, range +2, duration +1, +1 growing roots, +1 growing on uncommon « ground », +1 reasonable difficulty check).

What do you think about it ?
I’m not sure about :
-The spell guideline to use
-Does the plant have to be supernatural in order to grow on a human body ? (Meaning it requires a level 40 base effect)
-Both the Finesse and Athletic Check and difficulties
-The Form prerequisite (defining the allowed targets)

Sounds to me more like a Muto Corpus with Herbam prerequisite...

In any case, perhaps you will want to check CrAq poison guidelines or PeCo create wounds guidelines to set the level of effect (if you want to allow a check to resist is first is best).

I would look at The Verminous Infestation (A&A p.30). Of particular note is the Perdo requisite that is not otherwise required for worms. The Corpus requisite is need for the substrate when the worms cannot be seen, but that doesn't mean it wouldn't be needed here.

I don’t think it is MuCo. That would change the head of someone into a plant thing.

I neither want a poison effect though it could give an idea of a magnitude for a similar effect.

And I don’t see where a Perdo requisite is needed for my Herbam spell, growing roots is a natural process for a plant and it is the conjured flower’s business, not the Maga. But the quick grow may require additional magnitude, according to the Herbam guidelines.

It seems a simple spell casting a wood spear would be more efficient. Brutal but accurate.

I could see a perdo-corpus requisite to weaken the flesh so the plant can dig in properly, however I would probably accept a CrHe(Co) spell in most cases without the requisite in my own games.

Most of the time the simple direct approach is more efficient. That doesn't mean its what people want, though. I can create a spell to do a lethal wound, or I can create a spell that uses Faerie Magic to strike your entire bloodline with magically-induced leprosy. Which magus are you more afraid of angering?


Here's how I see it:

The easiest way is if my sigil involves plants, in which case, it could be a simple PeCo with plant CGI. No targeting roll needed.

Otherwise, if I want to create a plant, first I have to spec out the plant, then I need GM buy in, and if there is no plant that naturally has this effect, that plant will have to have appropriate powers, which involves the plant having Might. So we probably have an expensive CrHe spell. Again, no targeting roll should be needed: If my CrIg can place fire where I want within Range, why not CrHe? Of course, if my plant has volition, I might need Rego.