Agganar's Lightning Saber

The wood of a sickle, dagger, or scimitar you are holding is imbued with the power of nature's fury. For the duration, you can use your spellcasting ability instead of Strength for the attack and damage rolls of melee attacks using that weapon, and the weapon's damage die becomes a d8. The weapon damage type becomes lightning damage for the duration of the spell. The spell ends if you cast it again or let go of the weapon. Additionally, you can cause lightning to leap from the target to a different creature you can see within 10 feet of it. The second creature takes lightning damage equal to your spellcasting ability modifier.

This spell’s damage increases when you reach certain levels. At the 5th level, the melee attack deals an extra 1d8 lightning damage to the target on a hit, and the lightning damage to the second creature increases to 1d8 + your spellcasting ability modifier. Both damage rolls increase by 1d8 at 11th level (2d8 and 2d8) and 17th level (3d8 and 3d8).