Black Fish

Black Fish(흑린, Heuk-rin) is a Shinsoo technique that Scouts use to block out the light of the Lighthouse. This allows the scout to become "invisible". This is both used to hinder the attack of Fishermen and Spear Bearers. And it's just as important to help the scouts' observers as they like darkness.

(Heuk-rin's name means that like a waving black feather, it blocks out the light.) Of course, the Light Bearers can use reverse techniques to block the blocking spell.