虚空第零加护 (Áka Si Anse, アーカ シ アンセ, Āka shi anse)是在大战时期由森精种利用他们的创造者卡伊纳斯的力量加护创造出的一种法术武器。这种武器与幻想种有着密不可分的关系，因为其原理是引爆幻想种的『中核』，并用『术炉』将其力量引导释放。虽然其威力不足以击穿神灵种的神髓，但幻想种毁灭的强大力量也足以使森精种与地精种的髓爆以及位于阿邦特·赫伊姆之上的战神和天翼种们对峙。除了与其他势力对峙的目的之外，虚空第零加护还有另一个用处，即击穿
After returning to Riku's home base, some time later Shuvi points out that the location Riku is pondering is where they first met. Riku explains that he's had a hunch that something was off about that place but he couldnt put his finger on it. With the assistance of Shuvi, they arrived to their desired location and quickly pointed out certain abnormalities in its condition being far too unharmed compared to the surrounding area. Its discovered that its a hidden Elven facility for research and development of new spells/weaponry. Shuvi inspects the magical imagery surrounding the area and points out that the power emitted from the areas have been tampered with by an Old Deus, specifically Kanias. Both Shuvi and Riku first hypothesize that its some sort of protective spell, but quickly realize that they are not protective glyphs or rites of any kind, meaning its an entire new form of how magic is now integrated within the world. Riku points out that this new technology could be extremely destructive, and makes a remark that the Elf race is almost as hell bent on seeing the destruction of the world as the Dwarf race. The Áka Si Anse is then discovered by Riku and is described as "proof of concept reactor." While Riku can indeed read the Elvish language, he finds it difficult to read certain parts of the file on Áka Si Anse. It is speculated that a new form of secret language was developed so that only a select few could be privy to that information. This is speculated by Shuvi who states that its "Most likely written in code... Encrypted..." And mere moments later, both are discovered by the security system, in which Shuvi does her best to direct more of the fighting and damage onto herself. This is also when Shuvi first displays the Ex-Machinas special skill of being able to analyze and copy an attack after just once use, though only at 10% of the original strength.
虚空第零加护是森精种花冠卿——辛克·尼尔巴连一手策划的『虚花计划』的产物。 The Elves temporarily became allies with the Fairy's during Riku’s plan to end the war. This is only possible because he played multiple games with Shinku Nirvalen and told her the Dwarves' plan with the E-Bomb, and their current information on Áka Si Anse.
The Áka Si Anse, Heaven's Strike, and E-Bomb were all used in Riku's plan to reveal the Suniastor.