Bond of Fatal Touch

You invoke the blessing of Kelemvor onto a non-magical melee weapon; the weapon is imbued with  a power that mimics that properties of Kelemvor's personal weapon, Fatal Touch.

The imbued weapon becomes a magic weapon with a +1 bonus to attack rolls and damage rolls. In addition, the weapon does an extra 2d6 radiant damage against undead creatures. 

At Higher Levels. When you cast this spell with a spell slot of 5th level or higher, the bonus increases to a +2. In addition, when you hit and undead creature with the melee weapon attack, the undead creature must make a Wisdom saving throw against you Spell Save DC. on a failed save, the target has disadvantage on its attack rolls until the start of your next turn.