Vicious Blade

Summon one of three different weapons:

Longsword, Double-Bladed Scimitar, or a Greatsword

The weapons damage is treated as magic for the purpose of bypassing resistances and the weapon gains an extra d6 in damage. This damage is either Necrotic or Cold damage. For every creature killed with the summoned weapon, gain a +2 to damage up to a +6.

Only one weapon can be created at a time.

When cast at higher levels, move the extra damage die up one level per every level cast above 4th. At 5th level, the die becomes a d8, at 6th a d10 and so on.