The summoners code doesn't require you to build a certain way. If Riot wanted to restrict Karthus to AP, then they would remove all AD items from his store.

Technically you're only bannable with an AD Karth build if your tam reports you for assisting the enemy team.

Now whether AD Karth is assisting the enemy team or not depends on just how dumb the player is.

Buying AD items does not mean you are assisting the other team, and you shouldn't get banned for that.

Saying things in chat like "We're doing dragon now" or "Our jungle is stealing your blue" - that is assisting the other team.

It should be a bannable offense, even ad lux makes more sense than ad karthus.

With ad karthus you are basically a slow moving guy with only one skill usefull to your build (the wall).

People have the right to not participate in your "tests" so next tinme test things in a custom game with your friends or queue with 4 more friends that accept to do the test with you and not with strangers.

Negrojefe, no where in the code does it say, you must build a certain way, or play certain characters in certain roles.. This is an invention of the meta.

I can take AD LeBlanc in the Jungle if i want to every ranked game, and I should not get banned. Unless you have a red post stating otherwise?

They should just remove the store and introduce a sliding bar that has sustainability and damage on opposite sides and you move the bar for how much you want one over the other and the game always gives you the most optimal item for you based on how much gold you have and what the other team has