The master of World 189 was different. Refusing the spaces' proposal was one thing, but killing a space's envoy was a slap in the face of the spaces.
If you refused to let the spaces deploy Explorers, at most it meant you did not want to play with them. Killing someone, however, was a provocation.
How did End Space handle it?
End Space did not handle it.
When Lu Li dug up this old account, he was also puzzled. Doomsday, why were you such a coward? Didn't you have Manjushage?
Only after asking did he learn that Manjushage had not yet become a Supreme Taboo at the time. She had merely been at the Ninth Order Peak.
Simply put, End Space had no Taboo-level existence it could openly dispatch back then, so naturally, it had no way to regain its dignity.
Later, Manjushage attained the Dao, and End Space gained a powerful expert to hold the fort. But as Manjushage herself had said, her situation was special. End Space generally did not allow her to act rashly, preferring for her to stabilize the space.
Moreover, True Martial Emperor Lord had killed End Space's envoy two or three epochs ago. If they only remembered to seek revenge now, then even if they sent Manjushage to kill True Martial Emperor Lord, it would not demonstrate the spaces' might.
After all, if you were truly formidable, shouldn't you have killed someone the moment they provoked you?
On top of that, the War of Taboos involved too much. Manjushage had only recently become a Taboo, and her strength was still unstable. This was not a war they could certainly win. If the battle dragged on for several epochs without a victor, End Space would still have nowhere to hide its shame.
And so, the