Elemental Enchantment

You touch a weapon, granting it 1d8 of one damage type of your choice: acid, cold, fire, lightning, or thunder. If you cast this spell on the same weapon every day for 1 year, the effect becomes permanent.

At higher levels When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.