Web of Lies

Choose three creatures who are nearby, this spell has no fixed range but you must be able to walk between each of them in the casting time, and force them to make an Intelligence saving throw. On a successful save, the target is unaware that you tried to cast a spell on it.

On a failure, the creature believes that one of the other targets has committed some great betrayal against it, and that target becomes the creature's rival; it is unaware that it learned this information from you. A creature may only have one target as its rival, but can be perceived as a rival by any number of creatures. This information can be fictitious, however if you include some dirty secret of the target or its rival as part of the Verbal component for the spell, the creature has disadvantage on its saving throw. This spell has no effect on creatures with an Intelligence score less than 4.

The GM ultimately determine's how each creature responds to this new rivalry; for instance a knight may demand a duel, while a noble may begin plotting their rival's social or political downfall. 

At Higher Levels: When you cast this spell using a spell slot of 7th level or higher, the spell's duration increases to 1 week. If you cast this spell using a spell slot of 9th level, it lasts until dispelled.