Shirakawa Shuu proposed a deal to Xiao Ran, one concerning La Gias, the Underground World. The only condition was for Xiao Ran to subtly let Masaki know that Shirakawa Shuu had gone to La Gias, then send a few people to accompany Masaki. In return, Xiao Ran would receive the technology he had always wanted—the Relative Annihilation Engine—as well as the magic Shirakawa Shuu offered.
This deal did not even require Xiao Ran to do anything personally. A few words would be enough to complete it, making the cost practically zero. Even if he was worried about danger and refused to send anyone from his own team, he could still get what he wanted by merely having those plot-armored guys from the Steel Dragon Squad follow Masaki.
The Relative Annihilation Engine was an engine created by Shirakawa Shuu through improvements to the Black Hole Engine, supplemented with La Gias alchemy and magic. Xiao Ran did not know which was superior, but judging from its performance, the Relative Annihilation Engine's output should have exceeded that of the Black Hole Engine. As for by how much, there was no way to determine.
After all, the Black Hole Engine was used on Real Robots, while the Relative Annihilation Engine Shirakawa Shuu had created was used on Super Robots. The latter naturally had greater output, but that did not mean the Relative Annihilation Engine was necessarily much more advanced than the Black Hole Engine.
In truth, after obtaining Fury's Ougang Extractor and sealing off the Black Hole Engine's backdoor, the Relative Annihilation Engine no longer held as much appeal for Xiao Ran as it once had. What he truly could not refuse, however, was La Gias's magic and alchemy—things that could upgrade Saki Maski's mecha, Camilla.
Saki Maski was rather special within the team