Bahamut's Gavel

Bahamut's Gavel (Maul, Legendary)
While attuned to this Maul you have a flying speed of 40ft, you gain a +2 bonus to attack and damage rolls.

In addition to the regular damage, add 1d6 radiant damage. Add 2d6 when used against evil dragons.

Through the heart of the matter: As an action you can cause the maul to rapidly traverse in a line up to 60ft, all creatures in this line must make a DC 17 Dexterity Saving Throw taking 3d8 thunder and 3d8 radiant damage on a failed save, half on a success. Then roll a DC 5 con save, on a fail gain a level of exhaustion. This DC increases by two for every time you use this feature.