Sword of Purple Soulstorm

White-Style Sword Skill: Lethal Move - Sword of Purple Soulstorm (화이트류식 검술: 살인기 - 자색흉혼검, Hwaiteulyusig Geomsul: Sal-ingi - Jasaeghyunghongeom) is a powerful technique of FUG's Slayer, White after changing his spirit sword to Spinel form. White attacked Kallavan with this technique to deal more damage to him. White released powerful blast of crimson purplish shinsu with abstract shape with a spectral image of an undead hooded king from behind.

Alternate Translations
白神式 劍術：殺人技 紫色皇魂劍 (Taiwanese LINE Webtoon Translations)
 * meaning: "White style - Swordsmanship: Killing technique - Sword of the Purple Royal Souls"