Hey, identifying the 'worst' champions is subjective, but in my opinion, these are some champions that are considered less desirable:
Urgot: Challenging playstyle and vulnerability.
Yorick: Lacks impact and versatility compared to other top laners, with weaker team fight presence.
Azir: High-skill-cap champion who requires precise positioning and team coordination, making him difficult to master and less effective in solo queue.
Skarner: Often overshadowed by more mobile and versatile junglers.
Aurelion Sol: Unique playstyle centered around controlling orbiting stars, making him challenging to pick up.