Dark Wings

You sprout a pair of fiendish wings on your back. If you already have wings, they become magically enhanced. You gain a Fly Speed of 50 ft. for the duration. When the spell ends, the wings disappear and the target falls if it is still aloft, unless it can stop the fall.

If you are knocked Prone while flying with these wings, you descend 100 feet on the turn when you fall, instead of 500 feet as other creatures do, since the magic of the wings slows your fall. If you start any of your later turns still falling, you can halt the fall on your turn by spending half your flying speed to counter the prone condition (as if you were standing up in midair). 

When a creature that you can see attacks a target other than you that is within 5 feet of you, you can use your Reaction to shield that target with your wings. That target gains a +2 bonus to AC against the triggering attack.

As an action, you can buffet creatures with your wings. Up to three creatures of your choice within 5 feet of you must succeed on a Dexterity saving throw or take 1d6 Bludgeoning damage plus your Strength modifier. A Medium or smaller creature without a Fly Speed that fails the save by 5 or more is also knocked Prone.  

Using a Higher-Level Spell Slot. The duration becomes 10 minutes if using a 4th level spell slot, or 1 hour if using a 5+ level spell slot. 

Based on the Drow of the Underdark 2nd edition spell