top 4 most powerful sailor senshi

1.sailor cosmos
Sailor Cosmos was a character who played an important part in the Stars arc of the Sailor Moon manga, where she was revealed to be the true form of Chibi Chibi (who had very different origins in the anime).
After Sailor Galaxia's death, Chibi Chibi revealed to Sailor Moon that her true form was in fact Sailor Cosmos. Her future, as told to the Sailor Quartet, was not a hopeful one - Sailor Chaos waged war against the universe, and everything and everyone Sailor Cosmos knew was destroyed to the point where nothing could be salvaged even if the war ended. Upset, scared, and unable to do anything, Sailor Cosmos ran away from her future, opting to go into the past to destroy Chaos before it achieved its terrible Senshi form.
To destroy Chaos, she decided that she also had to destroy the Galaxy Cauldron, and so in the form of Chibi Chibi she tried to guide her past self, Eternal Sailor Moon, towards that end. Even though Eternal Sailor Moon was determined to save the Cauldron and chose a different path, she nevertheless inspired hope in Sailor Cosmos with her power and courage. She stated that the Eternal Sailor Moon who had saved the galaxy was, in fact, the true form of Sailor Cosmos, and that once she had that same courage and strength, only then would she truly be Sailor Cosmos.
What happened to Sailor Cosmos after she sent the Sailor Quartet to the future in Act 52 was not specifically stated. She said that she would return to her own future, inspired by Sailor Moon's strength, and that she would resume her fight in order to reclaim the mantle that she lost with her cowardice.
Sailor Cosmos' nature was not entirely clear, and her appearances in Act 51 and Act 52 brought forth more questions than answers. It was stated by Sailor Ceres that she was the ultimate future form of Sailor Moon, but it was unclear whether Sailor Cosmos was the future self of the current Sailor Moon (thus making her Usagi's next incarnation after Neo-Queen Serenity), a reincarnation of the current Sailor Moon, a descendant of the current Sailor Moon, or even Sailor Moon from an alternate future. Naoko Takeuchi herself seemed to imply when questioned that Cosmos' true identity was intended to be ambiguous to everyone, including herself.
2.sailor galaxia


In the anime, Sailor Galaxia was the most powerful Sailor Senshi in the galaxy, and as such fought in the Sailor Wars against Chaos. In the great final battle, she trapped Chaos and sealed it within herself in order to save the galaxy. However, Chaos was too strong for her and she realized that it would gradually overwhelm her. In order to protect herself against that threat, she removed her Star Seed and sent it out into the universe, telling it to find someone who would welcome it warmly.
As she fell under Chaos' influence, Sailor Galaxia began to attack planets in the galaxy, destroying them and taking the true Star Seeds belonging to other Sailor Senshi. She gathered followers, the Sailor Animamates, in order to help her with this mission.
In the meantime, her Star Seed travelled long and far before it finally reached the Earth and found Usagi Tsukino. It then took the form of Chibi Chibi and masqueraded as Usagi's sister. However, Galaxia's Star Seed was the Light of Hope that Princess Kakyuu and the Sailor Starlights were searching for in order to defeat the legendary Senshi. With the help of the Light of Hope, Princess Serenity fought against Sailor Galaxia, and finally managed to free her from Chaos' influence. Galaxia then departed, leading all of the Star Seeds she had collected back to where they belonged.
3.eternal sailormoon

 In this form her fuku underwent the most radical changes; she no longer wore a tiara with a gold crescent moon on her forehead taking its place, her earrings now had a star at the bottom of each crescent moon. The choker is red with a dark yellowish orange heart and a gold crescent moon under it while wearing the same white wing barrettes in her hair. The collar itself is like her old one, yet its color is a dark blue with two gold stripes and in place of her shoulder pads, she wore short solid pink bubble-like sleeves with a red band at the end. In the place of her front bow she had a gold heart with a crescent moon at the bottom with what appears to be four angel wings comes out of it. Her gloves are the same as before, but with a red v-shape border on it along with a golden star. Her skirt is attached to her top in a red v-shape with a crescent in the center of the v along with three layers on it; the top layer is yellow, the middle layer is red and the bottom layer is blue. Her back bow had been replaced with a huge set of angel wings and two very long and thin red ribbons trailing down from them. Her boots were now knee length with v-shape borders with a crescent moon on them.
4.sailor saturn

Sailor Saturn's dominant color was purple (choker, collar, elbow fittings of gloves, skirt, and boots), and her accent colors were white (tiara gem, earrings, front middle of choker, and center of front bow) and maroon (front and back bows). Her choker had a white six-pointed star, her collar had no stripes, her shoulder pads resembled flower petals, and the center of her front bow was a white crystal, similar in appearance to Pure Heart Crystals. Her gloves were elbow length with elbow fittings unique among the Senshi. Her boots were knee high and laced up in the front.