These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 0.86 s (backtrack: 0/20).


The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by games-strategy/war1gus-3.3.2::gentoo
# required by =games-strategy/war1gus-3.3.2 (argument)
>=games-engines/stratagus-3.3.2-r2 theora

!!! The ebuild selected to satisfy "=games-engines/stratagus-3.3.2*[theora]" has unmet requirements.
- games-engines/stratagus-3.3.2-r2::gentoo USE="bzip2 -debug -doc -mng -theora -vorbis" LUA_SINGLE_TARGET="lua5-1"

  The following REQUIRED_USE flag constraints are unsatisfied:
    theora? ( vorbis )

  The above constraints are a subset of the following complete expression:
    exactly-one-of ( lua_single_target_lua5-1 ) theora? ( vorbis )

(dependency required by "games-strategy/war1gus-3.3.2::gentoo" [ebuild])
(dependency required by "=games-strategy/war1gus-3.3.2" [argument])