I think it has to be either Anubis or Ymir. These two are some of the older models in Smite 2 and they really benefited from the quality of Smite 2. I think I'll give it to Anubis though, his ultimate animation is quite eye-catching.

Short answer: Jing Wei. I've mained Jing Wei since the moment she got released in Smite 1. She was my first diamond character and the one I have the most worshipers on! I was pleasantly surprised when she got announced in the roster of Smite 2 and I'm more than impressed about all the changes they made to her kit. Visually she looks very similar, but her quality and details are so much cleaner! I can't wait to level her up to rank 10 in Smite 2 as well.