If you're like me, you find off topic comments frustrating... but, this isn't exactly off topic.
I don't know if you ever take summoner suggestions to heart, or if you only coddle your own babies... but... have you considered making an item that suppresses location alteration spells/abilities? Something like Shifting Space on my champion idea The Onryo.
This would have to be a high cost item with a long cooldown, as it would either disable or remove the effect of flash, ghost, and abilities that allowed someone to move faster than their movement speed.
It's primary purpose would be to inspire high mobility champions to think a second before jumping on a plodding target.
Perhaps a set of boots called Boots of the Void, which gave 2 movement and this active and cost 1000 gold.
I like the concept as it could be used defensively or offensively. It would address flash abuse and champions with high mobility: Ahri or Kat.
Anyway, I'm not sure if you read through all of these posts or cherry pick things to respond to.
If you read this I appreciate you taking the time to!
TO ALL OTHER SUMMONERS, I would love to find support in this idea so it would garner the attention of Xypherous, Morello or one of those other great minds at Riot (continues to kiss up).