Turner of the Wheel.
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 weapon’s ultimate attack “Transmigration Into One” can be activated by calling its 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, resembling a black hole, causes a huge explosion.
…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 Material: Encyclopedia of Fate/EXTRA