Berserker special skill, linked to Battle fury.
Also translated as rage blade or raging blade or sword rage.
Reach a certain level/intensity of rage.
The berserker sword start to glow, with a red glowing light.
Mana consumption ???
By adding extra mana output, the berserker can release a highly damaging wave of energy
In Las Phalax, Seoyoon is able to inflict considerable damage on a boss level monster with at least a 100 level advantage on her (name and reference need to be added)