This genjutsu traps a victim in a powerful illusion, with no necessary eye contact; similar to Ephemeral, however, direct eye contact can still be applied when using this technique. When used, the genjutsu projects a torrent of crows, leaving the opponent at the user's mercy.
"Shin" (蜃) is a kind of aquatic, shape-shifting dragon, in the form a giant clam. It is said to be able to cause mirages and Fata Morganas. In fact, its name has become almost synonymous with "mirage": in Japanese, the word for "mirage" is 蜃気楼 (shinkirō, Literally meaning: shin breath tower).