The Lee Sin Q + smite combo is overpowered in both high elo and competitive.

I can't count the number of times a lee sin has stolen a baron from me.

Out of all the smite wars I've lost, lee sin has the majority of the wins. The ability to Q smite on baron has almost no counter play at all because it is the most convenient form of instantly extending the damage of your smite.

I'm only suggesting that you nerf the damage to epic monsters so that there is more risk involved in making the play and reduce the effectiveness of the combo so it isn't as reliable. This happens almost every single time I go against a lee sin and it is extremely difficult to avoid and on the other hand incredibly easy to pull off.