Added the unique skill "Power Critical"

Althena now has the unique skill "Power Critical". The holder of this skill will always have +10 Crit value, and the Might of the Critical is set to Attack Power x 2 (maximum 120).

This skill follows the specifications of the original Critical. Including the activation condition of Wrath, and Pursuit Critical Coefficient, I felt that simply replacing the unique system of the original work would reduce the fun, I thought it would be better to restore it as a skill for a specific unit. So I did it.