Feels overpowered. Personally i'd change the common weapons to give +1 rather than 2x. I'd make the comparison to the suits symbols (hearts, diamonds, clubs, spades).

Overall love the mod though <3

I agree that it feels overpowered at times. I think I agree with hshah that it should be an additive bonus instead of multiplicative. Then maybe offset the nerf with the kunai and shuriken having different bonus effects of some sort? Or perhaps have one be rarer and still be a multiplier?
The other symbols are honestly perfect in my opinion. Dart is exactly what the target needed.

@hshah @Invenio

Appreciate the feedback. The common symbols will be getting a nerf in the upcoming future for additive bonus to common + uncommon weapons, while keeping the multiplicative bonus to ninjas. Another nerf upcoming will be that kunai can't buff kunai, but can buff shuriken and vice versa. Currently doing some research on some historic ninja weapons to add and nerfs will be applied then.

Possible alteration for Kitsune. Since Kitsune translates to fox, foxes are part of the Canidae family so I think it should buff dogs and or wolves instead of cats. Just a thought