Art that uses the wind’s movement boost to strike like lightning. Deals bonus damage when used on the first turn. In addition, power is increased if Sylph is summoned.
“Moving like the wind, I thrust forward so fast it almost seems like I’m leaving an after-image. The tip of my sword explodes straight through the tree trunk I’m practicing on. It’s a high speed dash so fast I can’t even keep up with my own movements. Using that, I can power up my Thunder Thrust!” - Luka
“This skill is much better than “Thunder Thrust”. Even though they cost the same SP, its strength is drastically more powerful. If you use it on the first turn, the damage is also increased. In addition, if you have Sylph summoned, the power is further amplified.” - Alice
“The Death God Girl Thanatos used this skill to sever the lives of hundreds of humans.” - Alice

Lightning Sword Flash is an upgraded version of Bloody Fissure Thunder Thrust, as well as the first elemental sword technique Luka learns. Alice teaches it to him after he defeats the Scylla. It uses the speed of wind to deliver piercing blows.

Like its predecessor, it requires 2 SP, and damage is increased on its first turn. However, unlike Bloody Fissure Thunder Thrust, Lightning Sword Flash’s damage is increased when Sylph is up.

Despite replacing Thunder Thrust, Luka is forced to resort to that skill after defeating Archangel Ariel, as Promestein disables his elements, but is soon replaced by Flash Kill while fighting Archangel Ranael.