I was thinking about this as well. I envision a luchadore being a frog (maybe from zaun sewers like Twitch?)
Passive - Every 5th Hit, Frog performs his signature punch dealing 15/30/45 bonus true damage
Q - Shoulder Ram - Frog performs a small dash (perhaps like rivens shield, maybe shorter) if it hits enemy champion, they are knocked back a bit (rammus like knock back) : with W active - Frog will dash further and straight through an enemy champion, slowing them instead of knocking them back for 10/15/20/25/30%
W - Bulk Up - Frog gains X% tenacity and changes Q, E, R effects
E - German Suplex - (melee range) Frog quickly steps behind target and delivers a suplex moving target enemy champion towards the direction their back was faced dealing X damage and stunning for .1/.2/.3/.4/.5 seconds : with W active - Frog will throw the target enemy champ further, deal more damage, but they won't be stunned.
R - Frog Splash - From leaps 250/350/450 units in given direction and comes landing on enemy champions dealing X damage. If it's only used on one enemy, it'll do increased damage. maybe something like 200/300/400 multi target, 350/400/475 one target : with W active - Frog gains vigor after landing and has increased movement speed for 3 seconds 10/15/20%
Edit: Displacement and CC ftw as a luchadore btw.
anyway I'm bad at spit balling but it's just an idea :P