Then it should worry you greatly that your team has so far been absolutely unable to create unique patterns with reused mechanics. I agree it should be possible theoretically; but I have no confidence that Riot knows how it's done.
Riven is probably the most boring kit that you could ever see on paper - eeeever. I mean, Fiora's kit has more unique and interesting stuff than Riven's - Fiora has riposte and blade waltz as being super marquee things.
Riven on the other hand is what? She has a short dash that deals damage - She has three of them, sure - but that doesn't really make it 'unique', just repeated - a pbAOE stun, dash + shield, ad steroid and cone nuke.
Uniqueness and novelty aren't really all that important as the execution of uniqueness and novelty - There's not a single unique or new mechanic on Riven's kit.. pretty much at all.