What's the counter to hyper-rushing light?

Light is a very late game comp and surviving with them that long can be rough - more so than normal, at least. The individual units also tend to be pretty lack-luster since they're... You know... supposed to die.

Getting assassins into their back line before the Light buffs start rolling in will hurt them a lot. Spreading grievous Wounds, more than any other arch-type, will cripple them. Dodge chance can help keep you're units alive longer, though buff stacking will cause their last few units will have so much attack speed as to effectively ignore it. Also, like Glacial, most of Light's damage comes from Auto Attacks, so Armor and Wardens can help.

Its not s specially good comp so most meta comps with healing reduction will beat it of hes not extremly lucky with rolls

Vayne has never given me any trouble. Might lose to a 3 star vayne w/ decent items early but more than likely, they get stomped later.. Unless rng is really on their side. Poison seems to counter everything.. See a Vayne, make sure to have an assassin to jump back there and kill her asap.. I do the same to counter teams w/ predator/kog.. Make sure to have a couple assassins to knock out the ranged dps sooner than later.