Twice Critical

Twice Critical, also known as the Hand of the Dragon is a commonly occuring Sacred Gear. It was the first form of Issei's Boosted Gear, and it is wielded by Siegfried of the Khaos Brigade's Hero Faction.

Apperance
Twice Critical looks like a gauntlet that manifests on the user's arm, leaving the wielder's fingers uncovered. The color of the Twice Critical appears to differ between users.

Siegfried's Twice Critical creates a silver Dragon Arm on the back of his body.

Abilities
Twice Critical is a Sacred Gear that doubles the power of the user for a certain time. Siegfried's Twice Critical is a Sub-Species that creates a third Dragon Arm on his back and doubles his powers at the same time.

Chaos Edge Asura Ravage
"Chaos Edge Asura Ravage" (阿修羅と魔龍の宴（カオスエッジ・アスラ・レヴィッジ） Kaosu Ejji Asura Revijji), also knonw as the Feast of Asura and the Demonic Dragon, is the Sub-Species Balance Breaker of Siegfried's Twice Critical. It allows Siegfried to create 4 Dragon Arms, each doubling his power. The Dragon Arms can also regenerate, as shown in Volume 11 where Yuuto Kiba successfully chops off one of his Dragon Arms but grows back to four in the next volume.