Please elaborate on the duration of this skill. Is it a 'simple Knock-Up, THEN knock-back two part skill', or is it something that happens while the disciple is moving over a small duration (think Wukong Ult from LOL).
If it is a 'simple two part skill', then here are my concerns:
IronFist Accomplishes the knock-up already.
If you consider that Ironfist already exists, then the 2nd part of TornadoKick Skill appears even more so to be a copy of Tremor (which works better because everyone is airborne).
I would prefer to see a newer more unique-to-HC mechanic, where there is AoE knock-up and a slight knockback for a short duration around the Disciple, creating a look that is more "Tornado Kick" (and yes it looks more like the Wukong ult too) than the 'simple two part skill'.
edit: Ideally it would spin the Disciple a bit while it happened, I agree.