Question Concerning Particles & Animations With Skins (Riven In particular)

Hey all, I had a quick question regarding the changing of particles, animations, dances/taunts, ultimates etc. among all league of legends champions. -My particular interest is in Riven, considering that the only two skins that considerably alter her kit visually are limited/near impossible to get a hold of [Championship Riven, and Dragonblade Riven] -Are there any other champs besides Riven who do not have a skin always available in store that alter her visual animations, particles etc.?? -My curiosity is due to the fact that to my knowledge every champion has a skin that is currently/always available that alters their animations, making the skin worth more imo than just a retexture

As a Riven main and lover, I would really like to see a skin that actually is worth 975+ RP, in that it does in fact alter her shield, Q, ultimate, or whatever it happens to be. Battle Bunny, Redeemed, and Crimson Elite are honestly ghastly skins compared to the various other champions' options

Any Information on this matter would be greatly appreciated.

Sincerely, Might be Gosu