King Acrisius of Argos learned from the oracle that he would kill the son born to his daughter Danae, so he imprisoned his daughter in a bronze tower.
Zeus turned into golden rain and met Danae, and gave birth to a child, who was Perseus.
After Perseus was born, Acrisius put Perseus and his mother Danae in a box and threw it into the sea. Zeus blessed the mother and child drifting in the sea and guided the box through the wind and waves. Finally, the box drifted to the island of Seriphos and approached the coast.
There were two brothers on the island, Dictys and Polydectes, who ruled the island of Seriphos. Dictys was fishing by the sea when he saw a wooden box floating in the water, so he quickly pulled it ashore. When they returned home, the two brothers felt very sorry for the abandoned people and took them in.
Polydectes, Dictys's brother, fell in love with his mother, the beautiful Danaae, and wanted to send Perseus away to prevent him from ruining the relationship between him and his mother. Perseus had seen through his true colors, and at a banquet hosted by Polydectes, he offered to give Polydectes a gift, but Polydectes maliciously asked for the head of Medusa, the youngest sister of the three evil Gorgon sisters, known as the "Snake-Haired Demon".
Medusa was once a beautiful goddess, but was cursed by Athena and turned into a body with a rattlesnake, hair with venomous snakes, skin with bronze scales, and golden wings on her back. Anyone who looks into her eyes will be immediately turned into an ugly stone sculpture—just defined as "ugly." However, everyone who has seen the image of Medusa knows that although she is a woman, she is actually quite beautiful, whether it is a portrait sculpture or a card face set by Type-Moon. (Friends who are interested may wish to take a look at the sculptures that have been passed down to this day, they are really beautiful.)
Young, resolute and courageous Perseus was not afraid of challenges. He packed his bags and set out on his journey.
The gods blessed this brave young man (Athena wanted to kill Medusa once and for all and secretly planned everything).
Hades lent him a cloak, Athena lent him a shield, and Hephaestus lent him his flying shoes and snake-hunting sickle. With these treasures and his own wit and strength, Perseus successfully cut off Medusa's head.
After Medusa died, her head still retained the terrifying ability to turn into stone. In order to avoid being turned into stone himself, Perseus put Medusa's head in a bag he carried with him and presented it to Athena.
After Perseus died, Zeus raised him to the sky and he became the "Perseus constellation". This well-known legend was sublimated into an extremely powerful treasure.
The "Medusa-slaying sickle" made by Hephaestus is used by Shinji to slay the monsters summoned by Zouken and Caster.
The part of Medusa's head that petrified the swarm of imprinted insects is the petrifying magic eye "Cybele".
The thing that absorbed and sealed most of Zou Yan's soul was the "bag for monster heads".
What allowed him to fly under the night sky were the "feather shoes for walking in the air" lent by Hephaestus.
The cloak lent by Hades changed his appearance and concealed his figure.
The shield lent by Athena was used to block the tentacle's attack. Like Iskandar's chariot, it was a combined treasure and the only chance of victory Shinji found.
According to legend, after Perseus returned the shield and presented Medusa's head, Athena fixed Medusa's head in the center of the shield, turning the shield from purely defensive into an offensive and defensive treasure, truly transforming "aegis" from "Shield of Zeus" into "Shield of Athena".
Because the inlay of Medusa's head was done by Athena herself and was not part of Perseus' legend, Perseus's treasure is still the head and shield separated.
Petrification is a gradual process from the outside to the inside. Even with the highest level of petrification magic eyes like Medusa, it takes about ten seconds to petrify a huge tentacle.
The Eye of Medusa is the most energy-consuming of the several treasures listed. Shinji needs to concentrate all his magic power. During this time, he cannot use magic that strengthens his body functions. Ten seconds is enough time for the tentacles to partially petrify him and kill him.
In order to win, Shinji deliberately let the tentacles wrap around his body and materialized the shield first, regardless of the consumption of magic power. Under the protection of the shield, Shinji bought enough time and successfully reproduced the legend of "Athena's Shield".
Now, the shield belonging exclusively to Athena, the goddess of wisdom and war, is complete.
The monster queen of the Gorgons, the snake-haired Medusa, open your eyes!
The underground sewer illuminated by the golden light from the shield dimmed in an instant, just like the shadow in the center of the shield. Everything seen by the golden snake eyes was covered with blue and gray, accompanied by a slight "click" sound.
Under the petrifying magic eye "Kybele", anything with magic power level C or below can be petrified unconditionally, regardless of whether it is an organic life form or an inorganic non-living thing.
The tentacle monster was the first to be hit, with its skin beginning to turn into stone, and the signs of petrification soon spread to its mouthparts and stone.
At this time, the tentacle monster had not yet realized the danger and was still tightening. The friction and compression between the petrified part, which was not very hard, and the divine shield had only one consequence - it collapsed and turned into stone chips scattered on the ground.
After a few seconds, the tentacles in front of the shield were completely destroyed. The most important thing about a skill like entanglement is its continuity. If one part of it is out of control, the entanglement will naturally be released.
The crisis is over, and it's Shinji's turn to fight back.
He didn't bother to check his injuries. He put away the "Shield of Athena" immediately and launched a series of sickle attacks.
Now that he has obtained Perseus's treasure, of course he must use it well. Half of the physical skills that Shinji learned are related to the sickle blade.
Over the long years, Scathach has mastered the use of all weapons in the world, including the sickle. Under her guidance, Shinji has made great progress in the use of the sickle.
He no longer just relied on his strength and the special effects of his treasure to swing around randomly like he did when he killed Zōu Yū. He now knew how to hook, pull, flick, and cut, and how to combine various basic moves into combos.
This combo starts with using the outer blade of the "Snake Hunting Sickle" to cut diagonally from the upper right to the lower left, then using the inner blade to hook and pull with the backhand, and finally ends with a horizontal slash.
In the blink of an eye, the tentacle monster that had wreaked havoc and destroyed a large area of underground water networks was torn into pieces. The special effect of "bending and extending life" deprived the tentacles of their ability to regenerate, and it had only one end - destruction.
PS: Let me reiterate, Heroic Spirits do not have classes, and Perseus can only use one Noble Phantasm at a time, which is a limitation of the Rider class. Shinji has obtained all of Perseus' legendary Noble Phantasms, so as long as his magic power can support being fully armed, it is not impossible.
PS2: The best example of the petrifying eye targeting inorganic matter is in Chapter 7 of FGO, where Leonidas used his shield to block the evil eye of the demon king Medusa, but was petrified along with his shield.