Murky vs Li Li
Li Li will surprisingly kick Murky's butt every time. Murky should just focus on the minion wave as he can not do any damage to Li Li due to her heals. The only reason to engage Li Li would be to prevent her from getting to her team if a team fight broke out.
In team fights its better to target other squishies. If you are relying on Fish Tank pay attention to when you are blinded and bubble up at that point.