Master Yi Eternals dont display any skill expression what so ever
Master yi is pretty easy(braindead), that being said the eternals for him ask basically nothing from the players, and it doesn't show that riot understands the champion.
Master Yi eternals: Skillshots dodged with q: super basic mechanic, happens even without even thinking about it half the time. Double kills gotten during highlander: The king of multikills... and a celebration of double kills. Damage mitigated with w: can you press one of his skills? or is it to much to ask of yi players.
Even though he is simple, there is still some skill expression beyond being playing the game normally Examples: Tower dives narrowly escaped: surviving that last tower shot because you q'ed onto minion to drop agro or mitigated the damage using w (alternatively, lives saved with w would be much more impressive than damage mitigated) Dash following: since master yi q follows the target, if he predicts or reacts to opponent dashes, he follows them up. Example: enemy flashes during your q. Still happens just playing the game sometimes, but a whole lot less than just dodging skillshots Objectives soloed: yi has incredible ability for clearing neutral objectives. Hell, he can even solo baron before 22 minutes if he plays his cards right. Pentakills: If you are going to celebrate what yi does best, celebrate the correct number.
While even some of that stuff is pretty braindead, it means a lot more than "get a double kill"