After learning of the relationships between Tairde, Shadow, the Rotten Man, and Dorothea, Su Xiao basically concluded that relying on these people to help kill the Otherworldly King was hopeless.
Su Xiao rarely fought powerful enemies alongside others. He usually chose to fight alone, or gang up on enemies with Bubu Wang, A'Mu, and Baja.
When he joined forces with the Old Shaman against the Black King, it was because he and the Old Shaman had worked together in a world, and the Old Shaman was trustworthy.
The Sunlit Missionary Grounds were a tragic place. There were hybrids of otherworlders and humans, hybrids of humans and beastmen, and forced conglomerations of humans, otherworlders, and beastmen.
This was the pain caused by the racial war. Dorothea was helpless, Shadow was furious, and Tairde was unwilling to accept it—so unwilling that he had crawled back up after death and continued living like a corpse.
What Su Xiao truly wanted was an item or ability. Both Tairde and the Rotten Man had attempted to assassinate the Otherworldly King, and both had failed before even seeing him.
This made Su Xiao curious. How had the two of them broken through the heavy-armored troops' defenses? Under normal circumstances, given Tairde and the Rotten Man's strength, if they encountered the heavy-armored troops inside a building, there was no way either of them could survive.
Su Xiao was certain of this because he was confident he could butcher Tairde and the Rotten Man at full strength. Even if they joined forces, he could hammer them until they questioned their entire existence. As for Shadow, she was somewhat difficult to deal with—but only somewhat.
More importantly, counting the beastman Tairde, Shadow, Dorothea, the little girl, and the Rotten Man, there were only five people. Reincarnation Paradise had previously