How about something to help against those critters who need a little extra to take down?
Casting Time: 1 bonus action
Components: V, S
Duration: Concentration, up to 1 hour
You touch a nonmagical weapon and choose a material type. Until the spell ends, that weapon is coated in a thin layer of that material allowing the weapon to count as that material type to overcome damage resistance and immunity.
At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, you can touch one additional weapon for each spell slot above 1st. All weapons much be coated to the same material type.