I played La Tien Chi and faced La Ctis in a war in MP and even thou I was in a rather nice position, those freespawn chariots eventually overwhealmed.
Remember, with undead, throw in darkness, rigor mortis and they become very, very fierce indeed. Massed banefire on top really, really hurts.
Also, when I won as La Ermor the nation that give me most problems was La C'tis and those Sauromancers. Those Sauromancers spamming wither bones killed around 5,000+ undead and they were backed up with darkness/rigor mortis. Lucky for me by then I had tartarians, all the elemental royalty and Utterdark up, so everyone give in!
Respect the Sauromancers.