Azaronn's spectral barrage

As you point your finger at one creature within range and shout out an order to fire, the distant sound of cannons firing rings out and ghastly apparitions of cannonballs come soaring in from behind you.

Make three ranged spell attacks against the target, for each successful strike, the target creature takes 2d6 bludgeoning damage, if hit by all three attacks, the target is also knocked prone and has their speed reduced to zero.