banananamilk and I have been adding captions for SKY Castle.
https://www.viki.com/tv/36348c-sky-castle
However, we need a Korean mod to go over, check, fill empty segments, and lock the episodes. So far, 3 episodes are done and we are working on episode 4.
Please contact the CMs if you are interested:
https://www.viki.com/users/sita24
https://www.viki.com/users/eun_soo_lee_2/overview