Extreme Tornado Slash is Homura and Rin's Secret Fusion Ninja Art is Senran Kagura 2: Deep Crimson. It requires at least 3 ninja art energy scrolls from both of them to use. Like all Secret Fusion Ninja Arts, its power increases with the characters' mutual Affection.
Homura and Rin prep before they both leap into the air at once. They appear for only a split second before disappearing and slashing apart the surrounding area at blinding speeds. This creates a whirling tornado of strikes from both parties, trapping any and all enemies that are within range of its deadly embrace.