Tempest Griffon Feather Cape

You have resistance to lightning damage and make Dexterity saving throws to resist or avoid lightning spells and effects with advantage while wearing this cape.

While wearing the cape, you can use an action to speak its command word to transform into a bolt of lightning. When you do, choose an unoccupied space that you can see within 120 feet of you. You disappear from your current location and travel in a line that is 5 feet wide and up to 120 feet long to the chosen space. Any creature in the line or within 5 feet of either your old or new location must make a DC 16 Dexterity saving throw. A creature takes 3d10 lightning damage on a failed save, or half as much damage on a successful one. Once this property of the cape has been used, it can’t be used again until the next dawn.