To my knowledge, Tornado is a pet like rain powers are. Which means that the proc has a chance to tick every 10 seconds rather than on every time damage hits. Personally, I haven't tried it - Dorothy usually is knocking things back all over the place, so nothing would stay in proc range long enough to be worth the effort anyhow.
Yes, this seems to be the case. Also, in case anyone is interested, Lightning Storm procs per bolt not every 10 seconds.
I love the inconsistencies.
Currently on Virtue:
Jinrazuo - Crab Spider
RWZ All-Pylon Solo Run
It's not an inconsistency. Tornado's damage over time isn't a whole lot of rapid fire attacks, it's a damage toggle that works similarly to things like lightning field. Lightning storm works under a different rule and will inherit the proc from you, and its attack will have a chance to proc each time just like any player's attack would. Mastermind pets work the same way.
The problem is that I think tornado is bugged when it comes to procs and isn't working the way it should. From what I hear, there's only a chance for the proc to go off if you summon tornado right on top of an enemy and then never again. I've never tried it though.
I was looking at the available procs for Tornado and thought there might be some potential. Did some testing and never saw a proc trigger once.
Tornado really isn't DoT dmg so I wasn't sure if it was going to perform a proc chance on only the first hit or for every hit. So far I haven't seen it do either.
Has anyone had any extensive testing with this or any explanation?
Currently on Virtue:
Jinrazuo - Crab Spider
RWZ All-Pylon Solo Run