"Lady Ran... it's the vengeful spirits...!" Some of the scattered temperament particles from the lower world had reached the bottom of the upper world. When disordered and mixed-up temperaments happen to coincide with the grudge patterns of the deceased, the temperaments begin to act as robotic vengeful spirits. Although this is completely different from how vengeful spirits are usually formed, they appear to be fundamentally the same.

The word "shikigami" probably has a different meaning in the Hakugyoku Arena world. In this world, "shiki" stands for "formula." In other words, shikigami refers to spiritual beings who specialize in calculations. And apparently, this term does not indicate subservience to a master. This was why Reimu and the others got confused by the roles of Ran and Chen in this world.

"Chen, stay behind me. It's dangerous for you to charge ahead on your own." The two shikigami stood on guard by the underground lake. They were well aware of being youkai. And vengeful spirits are a youkai's nemesis by nature.

Vengeful spirits are a kind of phantom that are born from human grudges and malice. It is said that humans who go to Hell after death turn into vengeful spirits. Unable to reincarnate, they wander as phantoms for eternity. When vengeful spirits possess humans, the humans are forced to attack and quarrel with other humans. But when vengeful spirits possess youkai, they take over the youkai's mind. In either case, they are a significant threat to the existence of youkai.

"There… it's over, Chen." "A-Amazing! You're amazing, Lady Ran!" Ran made good use of her skills to turn the vengeful spirits back into the temperament particles they came from. Her onmyouji-like skills were extremely effective against the vengeful spirits. They were also quite effective in sorting out disordered temperaments. In the distant past of this world... Ran had acquired some skills without giving them much thought. And they worked like a charm as though it was all planned... as though everything was perfectly calculated. After this ordeal... Ran suddenly thought about the Yukari who was stolen from this world.