The Great Soul is the one responsible for bringing many of the residents of Taiko no Tatsujin to life, Don and Katsu included. She leaves Bachio Sensei to help teach Don and Katsu to become Golden Taiko drums before continuing her journey around the world to look for any who have the harmonic spirits within them.
The story's main antagonist. He was sealed behind a large door long ago, until Nemo, under Flip's misguided influence, accidentally releases him. He kidnaps King Morpheus in order to lure Nemo, and more importantly the Royal Scepter (which he and the other inhabitants of Nightmare Land fear), to his Nightmare Castle. Nemo barely manages to destroy the Nightmare King with the scepter and ends the evil king's reign along with Nemo's own nightmares.
The thirteenth Gung-Ho Gun and the most powerful, also referred to as "lost" number 13. She shoots giant red nails from a large briefcase that transforms into a crossbow. Like Vash, Elendira often acts childish and flippant, as well as flamboyant and sometimes extremely arrogant. She is a transsexual (some say she's actually a transvestite, but her body weight distribution and apparent slight breast development seems indicative of at least some estrogen treatment), and normally wears feminine clothing and a pillbox hat similar in style to fashions internationally popularized by Jacqueline Kennedy Onassis. However, underneath her outer garments she also wears restraining armour, and after disabling it, she is able to move at an even more inhuman speed than she is usually capable of. She seems to dislike Legato and fires a nail into Legato's torso in a conversation with him after arriving on a Zeppelin. It is also hinted that she holds some jealousy of Legato, commenting that Legato's lack of a number in the Gung-Ho Guns implies that Legato is on a whole other level from the Gung-Ho Guns, including Elendira herself. The only manga Gung-Ho Gun who does not carry one of the broken coins, Elendira did not appear at all in the anime. ::wikipedia::
The 60-year-old princess of Naratake castle.
Arrives at Miyano's place, wanting to release Lady Emmaniel, and chokes Kohta til he goes into unconsciousness. With Kohta bound by Elyse's contract, she saves him by controlling his knocked out body and slices Ares with her own weapon.
A masked Serial Killer who terrorizes the city of Lotto Valentino in 1705. Very little is known about him—not even his gender or approximate age. The Mask Maker's victims are all stabbed to death with a stiletto and their faces are covered with the same white mask worn by the killer himself. It is said that anyone who witnesses the Mask Maker will become his next target. (Source: TV Tropes)