I just started playing master yi (low elo) and I'm doing very well

On an 8 game win streak and have a 100% win rate on him O.o he seems OP right now. 3 pentas on him in 8 games. Shreds objectives and can 1v3 if played right with a little lead. Yes I know I'm bad and my ELO is silver 3 right now but still seems really strong and in my opinion he is the best champion to climb with in low elo. I've tried every lane many champs but I haven't found it as good with any other champ. I grinded out play ADC to gold 5 before but quickly dropped avging less than 4 deaths in a game because I had little to no map presence. I wonder if he's still good in high elo?