While testing monster summoning by using a debugger to force the
outcome, I saw "the renegade Angel of <foo> appears in a cloud of
smoke" as if only one such creature existed. Trying to change
that to "a renegate Angel" pointed out some problems: type names
like Angel, Green-elf, and Uruk-hai fool an() into using "the"
because of their capital letter. Fixing that was a bit of a hack
and worked for Green-elf and Uruk-hai but not for Angel because
it has the eminion extension so uses priestname() instead of the
guts of x_monnam(). Fixing that involved more hackery and now I
feel unclean, but it seems to be working.
It wasn't as noticeable as it might have been because most of the
time that "the Angel of <foo>" or "the priest of <bar>" was shown,
the caller is requesting "the" rather than "a/an".