Illness

Illness (イルネス, Irunesu) is the codename of a young woman dressed in a Gothic-style black and yellow dress, often carrying a matching parasol. A member of the Mask Makers, Illness is one of the four highest-ranked assassins of the group. She befriends Czes and Claudia on the trip despite her actual reason for being on the ship. Like Luchino, she has a tendency to get nauseous after a killing spree. Since infancy, Illness was worshiped as a god by a branch of SAMPLE and experienced constant abuse at their hands. When the branch was annihilated by the Mask Makers, she was taken in as one of them.

SAMPLE intends to use Illness for their own means, and after the events on "The Entrance" and "The Exit" she is kidnapped by the cult and is to marry their next god-candidate.

Chronology
In August 2002, the Businessmen (who are in fact the Mask Makers), after being confronted by men of a drug cartel, order Illness and Death to descend from the ceiling (where they are hiding) and pump them with lead. Afterwards, Illness falls sick due to the smell of blood and gunpowder and asks permission to vomit, then does so. The Businessmen, disgusted, and scold her for ruining their victory. Illness complains about the rodents in the ceiling as well as bad hygiene and wonders how the Businessmen can be so relaxed in the midst of slaughter before vomiting again (which results in more insults). Death is later killed by Angelo, who proceeds to kill two of the Mask Makers for drawing their weapons. Illness does not move. Instead, she starts a short conversation with him regarding her ally's death. Illness starts firing at Angelo, who dodges the bullets. He kills two more members  for drawing their weapons. The Mask Makers realize that any further attempts to kill him will result in their own deaths, and thus they choose to observe the situation instead. When Illness asks why he didn't shoot her, Angelo answers that he doesn't kill women and children. Illness thinks he is 'cool' and doesn't know what to do. Her teammates try to convince Illness that she has been insulted and that Angelo is sexist. Angelo escapes after the Mask Makers ignite smoke bombs.