Eightfold Blessings of Amaterasu on the Weight Stone under the Sunlit Watery Heavens (水天日光天照八野鎮石, Suiten Nikkō Amaterasu Yano Shizu-Ishi?, localized as "Eightfold Blessing of Amaterasu") is a mirror that Tamamo-no-Mae wears on her body. It is the temporarily released form of the Weight Stone of Tamamo (玉藻鎮石, Tamamo no Shizu-Ishi?), a sacred regalia among sacred regalia, which was enshrined at Izumo after being brought from heaven by "Takehinateru no Mikoto." According to the descriptions of the Nihon Shoki, it was taken from Izumo at the order of the Imperial Court and then later enshrined at Kawachi. It possibly later came to be known as the Yata no Kagami, the divine repository of Amaterasu, and it is thought to be the prototype of the To-Kusa no Kan-Dakara (十種神宝, ? lit. "Ten Kinds of Sacred Treasures") of the Mononobe clan, which holds the power to revitalize souls and life-force.
The mirror levitates around Caster in battle, which she uses it to hit enemies in close combat. She doesn't use this Noble Phantasm much, but once its function as a Noble Phantasm is activated, she summons a circle of levitating Ofuda surrounded by a number of glowing Torii, charges the mirror with energy, and stands in the middle of the circle to draw in the energy. The energy drawn in allows her to use her curses without the need to expend any magical energy for a limited time, comparable to performing as if she has an infinite magical energy supply. This is because the costs of using the curses are set to zero. It is normally a divine treasure of the land of the dead that can even bring the deceased back to life, done by deploying boundaries that can isolate the principles active in the world of the dead, but the Servant form of Caster hasn't been granted the authority to use that much power. Its rank as a Noble Phantasm is D, an awfully low rank contrary to its original rank, but that is because only a very small part of the original ability can be drawn out. Otherwise, it could have been an EX ranked Anti-World Noble Phantasm that has the range of covering a single country, and it could be used by Tamamo-no-Mae only while in her nine-tailed form.
In the first place, this Noble Phantasm was for nation building. A god's Authority that harvests the reconstruction of the dominions that were ruined due to an army of destruction. It can convert the power of all creation into an attack through using magical energy.
To activate the Noble Phantasm, Caster recites the following incantation:
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6
 Fate/EXTRA material - SERVANT Parameter and Skills: SERVANT CASTER, p.007
- ↑ 2.0 2.1
 Fate/Extra - Caster Matrix [T]
True Name: Tamamo-no-Mae
Noble Phantasm: The Eightfold Blessing of Amaterasu
Keyword: Maleficum, Red Lily of the Killing Stone of Nasu
Strength: -, Defense: -, Agility: -, Magic: -, Luck: -
Area Creation: C, Maleficium: EX, Transformation: A
Kewords Skills Details
- ↑ 3.0 3.1
 Fate/EXTRA material - Encyclopedia: Suiten Nikkou Amaterasu Yano Shizu Ishi [Noble Phantasm], p.191
- ↑ 4.0 4.1 4.2 Fate/Grand Order Material Book II
- ↑ Fate/Extella - Karna "だいいち、おまえの宝具はそもそも国造りのもの。その神威は、破壊の軍勢によって荒廃した領土の再建に取っておけ。"
- ↑ Fate/Extella - Eightfold Blessing of Amateratsu Description "鏡の形をした宝具であり、玉藻静石（たまもしずいし）という神宝中の神宝。魔力により万物の力を攻撃へ転化する。"