In my opinion, the best jungle champion to play in patch 13.5 depends on various factors, including your personal playstyle and the current meta. However, there are a few champions that have consistently performed well and are often considered strong choices in the jungle.
One such champion is Hecarim. With his high mobility and strong engage potential, Hecarim excels at initiating team fights and diving onto priority targets. His ability to quickly traverse the map and apply pressure makes him a formidable jungler in the current patch.
Another popular choice is Rumble. Known for his powerful AoE damage and crowd control, Rumble can control team fights and clear jungle camps quickly. His ultimate, The Equalizer, can be a game-changer in team fights and objective control, making him a strong pick for coordinated team play.
Additionally, champions like Udyr, Xin Zhao, and Diana have also shown strength in the jungle in patch 13.5. Udyr offers a strong early game presence and objective control, Xin Zhao excels at dueling and ganking, and Diana provides burst damage and scaling potential.
It's important to keep in mind that the meta is constantly evolving, and new balance changes can affect the viability of champions in the jungle. I would recommend staying updated with patch notes, professional play, and high-level solo queue to gauge the current strength of jungle champions and make an informed decision based on your preferred playstyle and comfort level with each champion.