Booster Salt

When you cast this spell as a bonus action, any familiar or construct that you or your ally controls, this magical pelt of salt will sprinkle on that construct or familiar, letting them gain a d6 bonus to their damage 

(Every time you cast this spell at a higher level, and with more salt you sprinkle, you add another d6 damage buff)

2d6 for lvl 5

3d6 for lvl 8