There needs to be some kind of "adorable kitty" Rengar skin
Seriously, nothing would tone down the frustration of getting one-shot by
than to be consoled by high-pitched little "mew" sounds whenever he leaps to kill me. Maybe even audibly yelling "HOOMAN!" while he does it. Maybe give him a dance that's just playing with a ball of yarn, or maybe pull out a table and slowly push a glass of water off it?
Make it happen