I compared each LoL champion's winrate across Bronze, Silver, Gold, Platinum and Diamond to see which champions perform relatively better at high elo compared to low elo. This list is the 10 that are most improved with more talented players.
#6 - Rengar
Come on, knife cat! If I had talent I'd probably play Rengar, personally.
Here are Rengar's winrates across the board:
Bronze - 44.11
Silver - 46.94
Gold - 48.08
Platinum - 50.52
Diamond - 51.59