User blog comment:Lykrast/Aughar, the stone mage/@comment-11284477-20140414220024/@comment-5686533-20140415091729

Passive is closer to that triggers on spell cast with a slow.

Q has nothing to do with, it's just delayed AoE dmg on a weird AoE, not knockup and no slow.

W is closer to a with a.

E is a small knockback, and not a AS slow like

R is on a target area, and it's rather small. That one would be closer to, except it has higher delay and slows during the delay instead of after the knockup, and is channeled.