No. 6

Sion gives up everything he has to escape No. 6 with Rat. They manage to arrive safely at Rat's home, but it isn't long before a black blister appears on Sion's neck, just like the one that was on Yamase's. Sion is in a great deal of pain, but Rat is able to save his life. However, his body has been completely transformed. Later, Sion and Rat analyze the black blister. They discover that it is the pupa of a special "bee" that infests human bodies and matures at a rapid rate.