Examples of Champs getting nerfed for being noob stompers.

I know Riot general balances around LCS, but elite players make up a very small % of the player base. The majority of the player base is pretty mediocre at the game. There 's a lot of champs that are currently strong in un-ranked and low rank levels, but rarely picked in high elo and pro's, such as etc. When was the last time a champ got nerfed who was basically never picked in an LCS match, and just stomped in bronze and silver?