User blog comment:Jopjopjop/Volume 20 Spoilers/@comment-50.139.232.230-20150731205208/@comment-77.105.25.94-20150806192256

Longinus Smasher is taboo power that Great Red gave to Issei first time in volume 12 (Ddraig said so) and he unlocked it in CCQ when Ddraig and Albion came to understand each other.