another project post: Project: Jhin and Riven would be great choices if project comes back next year
Just voicing personal opinion. Both fit the theme of being extraordinary beings with enhanced abilities. Jhin works well as a cold assassin who could plausibly have undergone enhancement in the pursuit of 'beauty', while Riven as a project skin could be a story very similar to her current one of redemption. Not to mention they use swords and guns, which are well defined in the Project Universe now.
I'd be interested in seeing how they chose Project skins this year--thought Jhin was a strong choice given they mentioned it in his Q&A and Riven too ever since that badass fanart.