Serene Demon Sword

''“Listen, first you need to put your sword back into your sheathe. Then entrusting your heart to the flow, you draw it and strike forward in the blink of an eye. In other words, it's the ultimate Iai attack that can only be used with a serene state of mind. An attack unmatched in speed that can only be performed with a serene state of mind... Its name is Serene Demon Sword.”'' - Alice

''“The Monster Samurai Elreena cut an entire group of attackers in half in an instant with that move. She was said to have calmly sheathed her sword as their blood bloomed like bright flowers from their standing lower bodies.”'' - Alice

Serene Demon Sword replaces Demon Decapitation when Luka learns it. It is a water and an iai type of skill that pierces through an enemy’s defense with ease. It is also known to strike far beyond a normal attack range.

Drawing the sword from the sheath and attacking with a fluid slash, it’s a 2 SP skill which does higher damage than a normal attack. Combined with Undine, this attack becomes significantly more powerful, and cancels Luka out of his Serene Mind state. At Undine Level 3, Luka is not cancelled out of his Serene Mind state, and simply does more damage with her power used. Overall, it is his most powerful technique, even above Vaporizing Rebellion Sword in terms of SP cost.

After the third battle with Granberia and Luka finished recuperating, Alice teaches him this skill as a “reward” for mastering the Serene Mind. Notably, Luka seems to master the technique far more quickly than others before, able to perform the attack the moment Alice tells him about it, even scaring her straight off the bat and leaving a huge gash in the wall of the room he was practicing in.