Blut die Schwester

Bloody Sisters.
A Noble Phantasm-like thing that White Berserker uses… or something like that.
Originally from the fighting game Melty Blood where it was Warcueid’s strongest attack.
In EXTRA this Noble Phantasm deals high physical damage, and applies the abnormal status effect of “Moon” which lowers the power and endurance of enemy servants.

It’s more White Berserker’s special characteristic than it is a Noble Phantasm.
It uses the relationship between the Earth and the Moon to affect enemies.
Originating from the brain of the Moon, it is the embodiment of the Moon that after many years became the Earth’s touch. This avatar possesses Earth‘s Authority while also being a copy of the Moon.
It simultaneously personifies the fundamental rules of both the Moon and the Earth, and by putting the rules of the Earth and Moon side by side it can use the discrepancies as a method of attack.
This includes the ability to bring the surrounding environment to her side (the Earth side), called Terraforming Attraction.
The gravity of the Moon is no more than one sixth of the Earth’s.
This remains unchanged in the cyber world. (All information inside Moon Cell is pulled toward the core by the core’s mass. This is thought to be what constitutes gravity in the cyber world.)
Everything that exists within Moon Cell obeys the rules of the Moon.
By using these truths this Noble Phantasm embodies the necessary concept and reduces the power of everything whose origin is the Earth to one sixth of its power. This effect is unable to be avoided no matter how much magic resistance one possesses as it is one of the world’s unavoidable rules.
(On another note, if the stage of battle is the Earth, this ability would turn into an Authority that would let her become a level higher than her opponent.)

…Well with that being said, it’s all conceptual, so explaining and understanding it is extremely difficult.
From the point of view of someone on Earth the enemy had their power reduced to one sixth, from the point of view of someone on the Moon the enemy had their power multiplied by six… both the Earth and Moon have their own point of view, but to be clear, this Noble Phantasm “reduce the enemy’s power to one sixth.”
To make it easier to understand,
When on the Earth, she boosts her own power.
When on the Moon, she reduces her enemy’s power.

Fate/EXTRA Material: Encyclopedia of Fate/EXTRA