help mid lane

So my friend and i switch roles for when we pla team, he goes mid and i go adc but in solo i still main mid. I want to play the champs he does because i know they can carry, he plays leblanc, anivia, cass, i currently play diana and annie (annie cause im good on her, he would olay her but hes bad at her), the problem is i really dont like cass' skill set i find it stupid, the problem i have with lb is shes bad at farming and doesnt really take towers like another ap, due to her slow attack speed.

So i guess who are champs like Leblanc, Cass and Anivia