Instantly silences target for 2.5 seconds and instantly burns x mana. OR
Squelch: Reduces a Champions AP by 20 + x/lvl for 4 seconds and burns 50 + x/lvl Mana AP(x) I think should be something like 10 and Mana(x) should be something like 15. (Kudos to Gale for the idea)

Mastery boost = next spell casted after being affected by squelch has 20% increased cost for 4 seconds.
Edit: Short ranged spell (300 range), to prevent from casting it just to burn mana.

Because melee shouldn't be the only ones shut down by a summoner.

This would be a great addition to get rid of that jerk that keeps stunning me and dealing damage. I'm pointing at you Malzahar!

me likey

#1 bump.

"burns x mana. "
Alistar hates you.

Very good well thought out idea, exhaust for a caster well, except leaving the escape mechanic of exhaust out

Most casters are already weak enough though.

And I don't think any of the nukers are OP.

Because casters are both prevelant and OP in the current metagame.

Right?

Exhaust: Slows you and you can't hit
Squelch: You can't cast abilities, reduces the amount of casts you have then makes them cost more.
they are completely different...
One seems OP hmm