New Summoner Spell Suggestion

Flash is such a go to spell in this game. While it is awesome I feel there should be some counterplay to it outside of it being on cooldown.

I present to you:

Anchor/Gravity Bomb/ Gravity (something to that effect)

Disable All Flash Summoner spells within 450 range. For 3 seconds your AD/AP are reduced by 10%. 320 second cooldown.