In the aftermath, the Ainu tribe was obliterated, erased from history by the victorious Shihōin and Feng families. Their story, their existence, and their culture were forgotten, save for one survivor—a woman who escaped to the human world.

This woman, scarred by the massacre, fled from the Soul Society and started a new life in the human world. She had a son/daughter who grew up unaware of his ancestral legacy. However, as Ivan matured, strange powers began to awaken within him

Location: Squad 2 Barracks, Soul Society

The tranquil atmosphere of Squad 2’s barracks is shattered when a powerful figure emerges in the distance. Ivan Usui, now a formidable warrior fueled by a deep vendetta, has returned to the Soul Society with a single, devastating goal. He stands outside the barracks and summons his Shunkō: Suijin Senkei (水神戦形, Water God Battle Form), focusing his energy into a massive, swirling tornado of water.

With a fierce concentration, Ivan unleashes the full force of his attack. The water tornado tears through the air, smashing into the Squad 2 barracks with overwhelming force. The entire building is caught in the destructive vortex, its structures splintering and collapsing under the pressure. The destruction is swift and thorough, leaving the barracks in ruins and sending a shockwave throughout the Soul Society. The massive explosion and subsequent collapse of the barracks quickly attract the attention of the Soul Society's most powerful defenders. Yoruichi Shihōin, ever vigilant, feels the immense spiritual pressure and recognizes the deadly intent behind it.

Yoruichi immediately activates her Shunkō: Raijin Raiju Senkei: Shunryū Kokubyō Raijin Senki (瞬閧 雷獣雷神戦形 瞬窿黒猫雷神戦姫, Flash War Cry: Thunder Beast Thunder God Battle Form: Flash God Black Cat Thunder God Warrior Princess). Her appearance shifts dramatically:

Soi Fon arrives she activates her own Shunkō: Mukyū Shunkō (無窮 瞬閧, Tireless Flash War Cry)

Yoruichi: (Eyes glowing fiercely, her voice crackling with energy) "Feel the wrath of the Thunder God