- "Give me a decisive battle, O Supreme God of War! Let the infidels' blood fill the spaces between the stars! Let's see now... the galaxy is about 120,000 light years in diameter... what would that be, 1060 cubic meters... wow, we're gonna need a lot of infidels to get that much blood. I'll get back to you on this one, O Supreme God of War..."
- ―Tsavong Lah, rambling in prayer to his crazy gods
Tsavong Lah, son of Czulkang Lah, son of Cobra-Lah-Lah-Lah, was the evil, scarred, ugly, ruthless Yuuzhan Vong "warmaster" who let his inferiority complex totally ruin what was otherwise shaping up to be a successful invasion of the galaxy.
He was a fanatical religious weirdo who constantly sacrificed captives to the God of War... not the video game, the Yuuzhan Vong god of war, Yun-Yammka. He planned the operation that led to the Jedi defeat at the Battle of Ithor, which ended with the entire planet of Ithor getting wiped out by a Vong bioweapon. Then he won other victories at Obroa-skai, Ord Mantell, Gyndine, Rodia, Nal Hutta, Duro... and wherever he won, he wrecked all the machines and droids on the planet and slaughtered tens of thousands of prisoners to sacrifice to Yum-Yammka. Tsavong Lah even managed to capture Leia Organa Solo and torture her... what is it with bad guys wanting to torture Leia?
Anyway, the turning point came during the Battle of Duro... yeah, he won the battle, but he got terribly distracted because Jacen Solo came on a rescue mission to save Leia. Tsavong Lah wasn't intimidated, because he'd heard Jacen was going through a pacifist phase. But when confronted with a scarred dude torturing his mother with slugs and beetles and stingrays and Yuuzhan Vong crap, Jacen went psycho with the Force and ripped off Lah's foot. With his pride as a bad guy wounded by losing to an emo Jedi wimp, Tsavong Lah started a crusade to wipe out all Jedi everywhere. He declared any planet that would capture and turn over their Jedi would be spared invasion... with special fabulous prizes for whoever could capture Jacen and Jaina Solo. He also vowed that if anybody was caught harboring Jedi... he would destroy their planet! Oh, and he also insisted that he totally won that fight against Jacen, no matter what anybody said, and he meant to get his foot chopped off. Then he genetically engineered a huge dragon-thingy and killed it, just so he could cut off its foot and then graft it onto his leg. Uh... well, it was supposed to make him look tough, but it didn't really work, and Tsavong Lah was quickly becoming a laughingstock. It didn't help that he lost a big battle at Fondor, and the tide of the war was turning.
He won back some of his reputation by totally pwning the New Republic by capturing Coruscant... and then totally destroying it and terraforming it with creepy Yuuzhan Vong creatures and plants. But even that didn't go very well. Jacen Solo had managed to become Best Friends Forever with the World Brain assigned to run
Coruscant's Yuuzhan'tar's new ecosystem, and the World Brain had become sassy and uncooperative, doing embarrassing things like putting spores into the air that made everybody itch, and discharging sewer-slurry into the streets... swarms of locusts, earthquakes, killing off the firstborn, dogs and cats living together, underwater oil leaks that wouldn't stop, and Tsavong Lah got pretty much all the blame. Lah was convinced that all the disasters would stop if he could just manage to sacrifice Jacen and Jaina to the god of war, but unfortunately, they were main characters in the series and thus untouchable. Lord Shimrra was getting seriously ticked off with him.
Finally, his big defeat came at the Battle of Ebaq 9, which was planned out by Admiral Ackbar as the ultimate "it's a trap!" for the Yuuzhan Vong. They lured Tsavong Lah into the system by using Jacen, Jaina, and dozens of other Jedi as bait. Then they hit his fleet with everything they had. Han Solo, Luke Skywalker, bad-ass Traest Kre'fey... even Keyan Farlander from the X-wing games made an appearance. They wiped out his fleet, while Tsavong Lah led ten thousand troops to hunt down Jacen and Jaina. He'd long since stopped caring about winning battles anyway and was more interested in revenge. But Jaina Solo kicked his ass in a duel, stabbed him through the neck, and that was the lame death of Tsavong Lah.
In the end, he was just another warlord built up by big victories, only to be humiliated and brought down by the Jedi main characters. Just like poor Grievous.