The sheila tag has three different sheila characters in it. Among the tag search results for sheila are the following:
one image from bastard!!, one image from final_fantasy_xi and the rest from mahou shoujo tai arusu.
The eva tag also is used for the character from mahou shoujo tai arusu but also for a character from metal_gear_solid series.
So some qualifiers are needed.
Updated by a moderator