Will

Will is mostly Hovernyan's favourite discipline because Hovernyan regrets fighting but does in sake of when fighting corruption. It is known for magic.

Origin
Will can be traced back to the Old Kingdom, from the birth of William Black. Not a lot is known of Black's childhood, but as an adult, he was able to protect his village from attack, as well as perform feats that would require the strength of ten grown men, with his powers of mind. These acts soon became celebrated as the "Powers of Will". After Black annihilated The Court and crowned himself Archon, his Will power had become so great that the world seemed to re-shape itself in accordance with his wishes; cities were erected in mere weeks, and machines were built that ran on Will power alone. His children also carried on the Will tradition, but with no enemies to fight, they grew petty and used their powers to terrorise the people instead of help them. After the Archon disappeared, his children began to vie for power. One of the Archon's commanded a great tower be built to channel Will energy. Just after its construction, a bright light filled the air and all of Albion shook. By morning, the tower was gone, the Old Kingdom lay in ruins, and Will power effectively disappeared from the world.

It wasn't until a mercenary and bandit by the name of Nostro met an old man named Scythe that Will power returned to the world. Scythe is speculated to be the first Archon, William Black himself. Scythe sensed that Nostro unknowingly carried the same power that all of his descendants had shared. Scythe taught Nostro how to be a leader of men, which included tutelage in the Powers of Will. Nostro then went on, with Scythe's sage counsel, to establish the Heroes' Guild. It was here that, amongst other things, that Nostro taught other Heroes to use Will power. Thus, Will users were reborn into the world.

It is unknown how Will is created, though most believe it is made from the soul or mind while others think it is from a unique magical trait in the blood. If only Black had this power, however, then it could mean any Will user is related to him. The three facts that are known about Will is that it is the energy that shapes magic into several powers that humans or the Earth itself possess, and that Will or magic cannot be destroyed, disrupted, blocked, or negated except by using other magical powers. People with strong control over their Will power may also bend reality to their own wishes and/or desires. In the Old Kingdom many things like Shards were powered by Willpower. This is another known fact about Will: while a Hero's Will might not be strong and their spells not powerful, the raw magical energy or Willpower itself cannot be blocked for there is no substance or material natural or created that is immune to Will and its effects.

It only goes for Hovernyan and Ai only... but few heroes also, have will power.

Singing
When Hovernyan sings a song, first time against Jack of Blades in dragon form, it is to make Hovernyan feel not regretful at all.

Singing a song DOES NOT reduce will power. Hovernyan actually have more power. When Hovernyan sings, Hovernyan has a chance to cry and feel anger while singing. When he sings during the fight, Hovernyan will be more stronger, resulting like destructions.

However, when Hovernyan sings a calming song, it is to soothe the people to sleep, resulting the snap the mind corrupted by the corrupted student.