Warcraft III: The Frozen Throne Walkthrough & Game Guide

Mission 8:  A Symphony of Frost and Flame
Moments later, at the Scourge stronghold, King Arthas and Anub'arak make their
final plans to defend the Lich King's Throne Chamber.

At the beginning of the mission while setting up your base take the obelisk to the
west.   Focus on only this location at first, let Illidan take the other 3 while
building up towers and an expo at the gold mine.   Once you get aboms and fiends
with web take out the blood elf base by doing tons of coiling and spamming locust
SLAUGHTERED IF YOU DO IT RIGHT, correct tower building includes building a
necropolis with your towers and upgrading it to atleast the halls of the dead),
then take out the  naga base.   Your only threat now is illidan and his naga.

Take the south obelisk and build some towers and necropolis, continue on to the
west, and don't even bother building towers if you don't want to, because you
should have tons of money, just keep on building abominations and fiends, make
your crypt and slaughterhouse a control group just spamming A and F like mad.
You should have tons of money because of your expos.  Just make sure to tower your
base well.  Using town portal is essential, as are meat wagons when taking out the
two bases (if you are being attacked while cleaning up a base finish a unit
producing building and then TP).  Money should not be a problem for you in this
mission, because the natural expo to the north of your original base, is open
right away and can easily be taken at any time, and is safe as soon as the blood
elf base is destroyed.   MAKE SURE TO UPGRADE YOUR UNITS!   Just go around after
you have crypt fiends and abominations and take each obelisk.   When you've got
all four of them you'll complete the undead campaign.