A student that has the requirements to have the Sign of the Very Old Ones, when you play the card, does not get it (even waiting a year).
I think that the potential bug is that the game checks if a student is elegible when they increase a level of magic, but the check doesn't happen when you play the card for the first time.
Unfortunately I don't have the screenshot with the requirements of the pendant, but I took the pic of the student without the pendant after one year.
A student that has the requirements to have the Sign of the Very Old Ones, when you play the card, does not get it (even waiting a year). I think that the potential bug is that the game checks if a student is elegible when they increase a level of magic, but the check doesn't happen when you play the card for the first time.
Unfortunately I don't have the screenshot with the requirements of the pendant, but I took the pic of the student without the pendant after one year.