Chakravartin: Turner of the Wheel (転輪聖王, Tenrin Jōō?) is the "minor" Noble Phantasm of Buddha, necessary to use his "major" Noble Phantasm Amita Amitābha. The term Chakravartin refers to the concept of the “ideal universal ruler” of the Vedic period of ancient India. It is a seven kilometer wide chakram of light that expands in the sky above Buddha, a weapon based on an implement utilized by usually unarmed Buddhas to defeat their enemies.
It slowly revolves in the sky, shooting arrows of light at enemies within the ring. It can be described as a "mobile artillery platform that can shoot in any direction," the ring of light acting like a rail on which the artillery platform moves along. The rings of light, reminiscent of rainbows, increases with each turn of combat, reaching a maximum of seven rings that correspond to that of the seven treasures the Chakravartin (ruler) possesses. Once all seven are manifested at the peak of battle, Amita Amitābha can be activated.
It shows the capacity to take over the Moon Cell Holy Grail War, completely changing the rules of the war. It breaks SE.RA.PH, and Rin Tohsaka speculates that it seeks to destroy SE.RA.PH. The Chakravartin envelops the virtual sky of the Moon Cell, each floor level became independent, and Masters are no longer forced to kill each other. Since Chakravartin has appeared, the Dead Face phenomenon began to perpetuate.
In the game development of Fate/Extra, Chakravartin was axed because of the production cost. Futhermore, Kinoko Nasu said that this level of visuals is something you have to do in an action game. However, Chakravartin was fully used in Fate/Extra Last Encore, the anime adaptation.
- ↑ 1.0 1.1 1.2
 Fate/EXTRA material - Encyclopedia: Turner of the Wheel [Noble Phantasm Name], p.198 [T]
Turner of the Wheel [Noble Phantasm Name]
This is Saver’s minor Noble Phantasm. It’s a weapon based on an implement used by usually unarmed Buddha to defeat their enemies.
Chakravartin (Turner of the Wheel) is the concept of the “ideal universal ruler” that was used in the Vedic period of ancient India.
The weapon Chakravartin is a 7km wide chakram of light that is expanded into the sky above the Buddha. While revolving slowly, it shoots arrows of light at the Servants within its ring.
Think of it as a mobile artillery platform that can shoot in any direction. The ring of light is like a rail that the artillery platform moves along.
The number of rings of light increase each turn, until it has reached the maximum of seven. These seven rings correspond to the seven treasures that the Turner of the Wheel (ruler) possesses.
The rings are reminiscent of rainbows, and at the peak of battle this weapons ultimate attack “Transmigration Into One” can be activated by calling it’s true name.
The rings of light combine into one with a clang and the ring starts spinning at high speed. Before long it morphs to resemble the ring that floats behind the Celestial Buddha Variocana, and pillars of light coming from the entire 360 degrees of the ring are focused on the player’s Servant, and the convergence causes a huge explosion that resembles a black hole.
…Well of course this is a written description that didn’t take production costs into consideration in the slightest, so of course it was axed. I guess if you want this level of visuals, you have to do it in an action game.
- ↑ Fate/Extra Last Encore - Episode 3: Golden Wild Hunt