Overview
Shikieiki is an alternate spelling for the character Eiki Shiki, Yamaxanadu, used in some Touhou Project games. Eiki Shiki (四季映姫, Shiki Eiki), in its Japanese naming format, is combined together as Shikieiki. There are many illustrations that are not tagged with the full name, but a partial match search for this tag does not find Eiki. If you do a partial match search for Eiki, illustrations with the full name and this tag will be included in the search, resulting in more hits.
For more details refer to the article Eiki Shiki, Yamaxanadu.