Re: Mid/late game defense against undead??
 

Flames from the Sky would be nice, since its effect scales with target army, but it's not exactly the easiest research. Battle spells that hit large areas or the entire battlefield can also help. Try to have your own necromancers, as well -- Wither Bones is unresistable.
Archers with Flaming Arrows activated could help. And a War Bow fires 13 arrows per turn... might be nice if you have a quick/precise commander.
Try to have an unbreakable, unfatiguable front line -- this usually means mindless summons such as living statues, clockwork horrors, et al. The priests and mages must be protected... at least there aren't that many Ermorian/necromantic fliers (Harvester of Sorrows, Lammashastas come to mind).

Re: Mid/late game defense against undead??
 

as they said, buy some cheap priest with a small buffer zone of troops to guard them, rack up temples to make priests.

either that or cast "reliven statues" til you puke, theyre the strongest summons per gems there is.

Re: Mid/late game defense against undead??
 

<font size="2" face="sans-serif, arial, verdana">That's probably a bit of an exaggeration. Tartarian giants cost only 10 gems each for example.

Re: Mid/late game defense against undead??
 

If your dominion is very strong then "Purgatory" is also nice.

[ December 18, 2003, 13:11: Message edited by: Bossemanden ]

Re: Mid/late game defense against undead??
 

Tatarians have nice stats, but weak defence...

You also only get 1 per cast where statues can net you quite a few at high levels.

The titans are also rather big, which means they can be mobbed by the undead, where the statues will be able to use their numbers.