Doubling all of our damage permanently is a rare effect, and Quest for Pure Flame (maybe the closest comparison) takes a lot of work to set up, so I guess that Insult may indeed be a rare (or at least an abnormally strong uncommon)
You have a land thats a 2/2 when you need it, and it works in multiples since one factory can buff the other
There are many situations when the ability may resolve without effect
She certainly has plenty to sing about, as questing with this Disney Lorcana: Rise of the Floodborn card allows one character card to be returned to a player's hand from the discard
An official lore guide says that they "infect" victims with splinters that start growing rapidly through their flesh, which is deliciously nasty
Furthermore, due to this sets scarcity, many of these cards have not reached the publics consciousness fully though notable cards like Fellwar Stone, Ball Lightning and Tormods Crypt all debuted in The Dark, alongside Sorrows Path, arguably the worst MTG card of all time