Ahri's Charm duration should be effected by range
The longer it traveled the longer the CC lasts. Full distance gets the 2 seconds on max level, while using it in your enemie's face results in a very short one.
Explain it somewhat like this: The charmed target can feel Ahri's true intent the closer it gets to the position Charm was cast on. Upon realizing the true intent it fights off the charm.
I'm fine with Ahri if that change goes through. At least her players will need the skill to hit a skillshot at a meaningful distance then.
it becomes permanent, makes him immune to both damage and CC, increases his running speed massively and have him follow Ahri for the remainder of the game.