Heaven's Strike (
It's depicted to be a sword/lance-like weapon of light made by channeling the spirit circuit's power within a Flugel's body and condenses it into one single, massive blow. During this, all the Elementals in the Flugel's wings resonate and glow. The attack itself is so draining that a Flugel would shrink to child size for years while also undergoing magical recuperation. It became the only named combat technique amongst the race that represented war itself.
The lance was strong enough to destroy the capital of Elven Garde in one hit. In V3C1(8 steps left), Jibril also mentioned that even three thousand elves could not block the attack despite their combined efforts (although they were able to save some buildings, such as the library Riku and Shuvi investigated). As a side effect, Jibril lost her powers for 5 years.
God's Strike Edit
At the end of The Great War, Artosh proclaimed he was tired of their pursuits and told the beings there no matter how hard they struggled, they were no match for the heavens. As the Aka Si Anse and E-Bombs were directed at the Flügels, they initiated Heaven's Strike and channeled the energy to Artosh to create a more powerful version of Heaven's Strike, a God's Strike (神撃, Shingeki) or Almighty Smite. The energy was powerful enough to penetrate to the core of the planet. It was pointed out by Riku that neither the Áka Si Anse nor the E-Bomb could match the power of Artosh's Godly Strike.