I was sold on the title.

When you say Yordle with a Sword, the first thing that comes to my mind is Kirby

I would like a skill called "Crutch shot" which slows the enemy to be on a yordle with a sword. I would also like it if the Yordle is obsessed with the death of all humans and is a yordle supremisist. When he kills a human he yells out "You're dead, Human scum!"

Well a yordle that hates human that could fit the global lore if for example our yordle estimate that humans are responsible for Veigar's illness. Anyway you seem inspired you might want to create your own lore for this concept:
Check out here!

"Crutch shot" Within the whole mecanics that could be the "E" 's first passive animation that can be fun indeed lol.

He's so kawaiiiiiiiii

Finished my lore.
http://na.leagueoflegends.com/board/...1#post32534020

sounds really cool, but it also seems a little complicated and confusing.
the art is actually very good, even the old version.
it would be awesome if this got into the game.
good luck mate!