Octavo

is a boss in.

Biography
CoH: is a musician and magician who played for the CoH:. Fearing the return of CoH:, CoH: bewitched the CoH: and attempted to steal the CoH:. However, upon being touched, the CoH: split. Despite this, CoH: was able to enchant his CoH: and transform it into the CoH:, granting him more power. Using this power, CoH: sealed CoH:, cursed the inhabitants of CoH: to follow a rhythm, and summoned an army of monsters across CoH:. He also placed various NaN Instruments deep within the dungeons of CoH: to prepare NaN Four Championss who could combat CoH:.

In addition to bewitching the CoH:, he also bewitched CoH: to fall asleep in CoH:, froze CoH:, and summoned monsters to the CoH:. To create the CoH:, CoH: stole the CoH:, CoH:, and CoH: from the NaN Fates.

CoH: can be encountered at the end of four elemental dungeons in CoH:, attempting to infuse the elements into his NaN Instruments to create his NaN Four Championss. When he is first encountered, he challenges CoH:, CoH:, CoH:, or CoH: in combat against his first CoH:. When met for a second time, he vows to not make the same mistake as before, pitting the heroes against his second CoH:. During the third meeting with CoH:, he insists that the heroes will never be capable of fending off CoH:. In the fourth meeting, CoH: reveals that he is attempting to amass an army to fight CoH: and summons his final CoH: in an attempt to make the heroes recognize this.

After the four NaN Instruments have been collected and CoH: has been infiltrated, CoH: greets the heroes and forcibly reclaims his NaN Instruments to empower himself. He then questions if the heroes can prove to be his NaN Four Championss instead, prompting them to battle him.

Upon CoH:'s defeat, a CoH: will appear and spirit away the CoH:. CoH: will blame the heroes for this and lament that CoH: cannot be defeated without it. He then travels to the CoH:, 25 years forward to a time when CoH: has taken CoH:. In the hopes of stopping CoH:, CoH: challenges him to combat, only to lose. CoH: is not seen after the defeat of CoH:.

Characteristics
CoH: is fought on a stage surrounded by monsters and possessed NaN Green Guards. Using the power of the CoH:, CoH: summons monsters by channeling the various NaN Instruments at his command. When these monsters have been exhausted, he will switch NaN Instruments. Upon exhausting the CoH:, CoH:, NaN Maracas, and the CoH:, CoH: will summon random sets of monsters with the CoH: until he has sustained enough damage. When he is struck after summoning random monsters, damage will be dealt to the CoH:, which has six NaN Hearts. In addition to summoning monsters, CoH: can conjure rows of magical NaN Swords or NaN Hammers in purple or green to damage CoH: and CoH: respectively. CoH: can also summon fireballs, which he casts in the shape of a chevron.

After the CoH: has been dealt enough damage, a CoH: will appear. The CoH: will fall into the CoH:, ending the battle.

Trivia

 * CoH: admits that CoH: reminds her of the Necrodancer, the primary antagonist from Crypt of the NecroDancer.

Nomenclature
CoH:'s name is derived from , an interval between harmonic pitches of different frequencies.