Kanchelsis's Gift

As a reaction the blessed may use the shape changer feature that vampires have.

Shape changer. If the vampire isn’t in sunlight or running water, it can use its reaction to polymorph into a Medium cloud of mist, or back into its true form. While in mist form, the vampire can’t take any actions, speak, or manipulate objects. It is weightless, has a flying speed equal to walking speed, can hover, and can enter a hostile creature’s space and stop there. In addition, if air can pass through a space, the mist can do so without squeezing, and it can’t pass through water. It has advantage on Strength, Dexterity, and Constitution saving throws, and it is immune to all nonmagical damage, except the damage it takes from sunlight.
 You can do this a number of times equal to your proficiency bonus.