The most costly of Luka's offensive skillset in terms of SP (at the count of 4), Death Sword Chaos Star is Luka's most powerful technique in Chapter 1 (not including the attacks used under the influence of holy energy). This skill hits an enemy 4 times for a great amount of damage. However, this skill's cost level has rendered it situational.
This skill is later replaced by Granberia's signature skill, Vaporizing Rebellion Sword.