These are all rituals so they’re all expensive to cast but likewise they’re all quite mean. The description of the parameter “must be cast on someone who has just made an agreement with the caster†makes things tricky. After all these spells aren’t nice, getting someone to stick around so you can line up a curse for them doesn’t sound like the easiest thing to do and for the most part casting these spells at arcane connection range would make them prohibitively high level. I decided not to worry about it and make them range eye.
There is also a bit of weirdness that I missed at first. The person upon whom the spell is cast is not necessarily the target of the spell. (Certainly their magic resistance applies to the spell but here are many spells where the magic resistance applies where the subject is not the target, take pillum of fire for example.)
It later occurred to me that a caster could create positive effects for the oath breaker after they’ve sworn a marginally silly oath. For example “I will not proclaim three times in a row that the magus who cast this spell is the best dressed and most well groomed person on earth because I know that if I do the terrible fate of turning into a brown bear until sunset will befall me.†This strikes me as not being abusive because the vis cost for this sort of arrangement will be far higher than creating charged items, and it is also almost certainly going to be a source of warping.
Oath breaker’s remorse
Creo Mentem 35
R eye
D bargain + moon
T individual
The target will feel an overwhelming sense of guilt and regret over breaking their agreement. The target must pass a personality test with an ease factor of 9 every day to resist the temptation to go to the magus and explain and apologize for their actions.
(base 4, +1 eye, +3 moon, +3 bargain)
Last breath of the betrayer
Muto Auram 45
R eye
D diameter + bargain
T part
After breaking the bargain the air that the target breathes will change into a vile poison as the bargain breaker breathes it doing +15 damage per round for the duration of the spell.
(base 15, +1 eye, +1 diameter, +3 bargain, +1 part)
Deceiver’s desiccation
Rego aquam 35
R eye
D bargain + moon
T individual
If the party that is subject to this spell breaks their bargain for the period of a moon any water or other liquids in their mouth will forcefully expel themselves. This will prevent the bargain breaker from consuming any liquids in a natural way.
(base 4, +1 eye, +3 moon, +3 bargain)