How are targeted spells programmed in this game mode???

I specifically focus light build, and I swear I will put all my energy into building one specific champ (Normally Vayne) and for some reason, champs across the map all focus just her. Naut, Kog, Tali, Raka, Syndra... it's like they all drop there spells on her and only her the whole game. Sometimes, when you go against more than one of these champs, it's like your 1 champ is obsolete because of the consistent CC or damage that's been done. You can't even counter play it no matter where you move the champ either.