In the final Night Elf mission, enable the whosyourdaddy
code then go down into the Undead base with any unit. Kill Archimonde
in one hit. Then, destroy Jaina's and Thrall's bases. In the sequences
where it shows Archimonde talking to Jaina and Thrall, Archimonde
will be gone but you can hear his voice and see the green circle
around him.