A Certain Magical Index: Touma Kamijou: Strongest Level Zero or Only Level Six?

In Academy City, a level zero is classified as someone with an ability that is very weak (or close to non-existent) or that which they can not measure. For those that have seen the anime know Touma's right hand is virtually absolute in nullifying the ability/magic it touches. Many students within Academy City aim to be at the never obtained level six.
So what do you guys thing; Is Touma the strongest level zero or the only level six?

I'd go by the definition that he currently would be a level zero until a method of measuring his ability is conceived. We all know he's powerful and can stand toe to toe with Misaka's ability.

 

Seeing that it is decided through measuring his abilities using the same methods as everyone else, I'd have to agree. Just because he can fight a level 5 doesn't determine he is a level 6 on that scale. So similar to what Hikikomori said, I think he is a level 0 until another scale is used.