What have you done riot?

So,i main Veigar from season 3 when i made my 2nd account.I bought him first and started playing with him. He was pretty overpowered,with his scaling on ultimate and his old q and e.I had very high win rate and i was not surprised when riot nerfed him in season 4.After that my win rate was about 50%.So it was ok,i could still 1-shot Katarina or someone else.But i cried after the mage update,now i cant even kill 3 12 Ekko because my only single target ability is an EXECUTE.I don't get it,Riot pls.