Heavenly Smite Skill Gem

I'm thinking 2h Mace / Staff skill with some punch.

multiplier: 200%

Swing your weapon at a single enemy, damaging enemies behind in a cone
On hit a stacking 20% less damage debuff is applied for 0.8s

With this skill you could play at a different pace than a blur of attack animations. You would choose which enemy to strike and this would reward skill over attack button spam.

Just my thoughts on something that would get me excited to play 2h.