Blades of Ice

You create two blades of ice, which hover around  your space for the duration, or until you use them to attack.  While they hover around you, each ice blade increases your AC by one.  As a bonus action on the turn you create them and on each of your subsequent turns, you can send one of your blades flying towards a creature you can see within 60 feet of you.  Make a ranged spell attack against the target, dealing 1d8 slashing damage and 3d8 cold damage on a hit.  The blade shatters at the end of its trajectory and is lost. 

Anytime you take damage while you have at least one blade hovering around you, you may use your reaction to sacrifice any number of your remaining ice blades, using them as shields to reduce that instance of damage by 1d8 per ice blade destroyed.

At Higher Levels:  When cast using a spell slot of 4th level or higher, you create one additional ice blade for each slot level above 3rd.