I found the raw for this scene and i can confirm. the raw says the attack releases infinite projectiles and Seiya is repelling them all.
This is not important, because a later scene changes the description and now the character only says that there are many, the term narrative hyporbole applies perfectly in that example, since it is only vague description and there is nothing to indicate that they are really infinite attacks.
In the Japanese manga it just says many or numerous (数多).
For example, in fiction you can find several characters who claim to move at the speed of lightning or the light speed, but they are rejected in the Wiki, because they do not meet the standard of such speed and it seems that their description is just a hyperbole, and this case seems somewhat similar.
I went back and looked at the raw mentioned and i can confirm. Again the Kanji for Infinite is used
Shura stops the first attack with the speed of light, which is the standard speed of a Gold Saint in this franchise, so they don't need infinite speed to block an attack with that description.
However; I will say there is far more infinite speed feats that happen as well not just these even the classic has a couple
The franchise has some examples that might indicate infinite speed for some characters, but the example given in the topic is too vague and even contradicts itself within the story itself.
this is just a general scaling chain not a specific one
Mariners < 7th Sense bronze bois < Gold Saints < 8th sense users < God Cloths < Sigurd < Golden God Cloth Seiya < 9th Sense Users < Gods
obviously if we did the proper scaling chain for every individual the scaling chain would be immense.
The God Cloths in the manga are golden (this is the franchise's canon shade for these armors), the Golden God Cloth does not exist in the main universe of Saint Seiya.
The Marines like Bian are described with a speed close to the speed of light, not with the speed of light, this is one of the reasons why the Gold Saints are superior.
Marines (near light speed) < Gold Saints (speed of light and can be increased when they go to the maximum or when they reach a miracle) / Various Gods < 8th sense users (probably even higher, because it is a power that the gods do not possess and is the ultimate sense in the manga) < Poseidon (or Olympic Gods in a human body) < God Saints (Hades Arc) and Gods like Hypnos and Thanatos < Olympic Gods to the maximum < Hades, Athena, Zeus and Poseidon to the maximum < Saori to the maximum (she has the potential to be more powerful than the mythological Athena) < Eris with power ups / Chronos.
Shura is a gold saint, by default he’s experienced with the 7th sense and is never not gonna be using it in a fight. Why is this important again?
Well, I will expand on this comment. The Golden Saints start with the speed of light, this is the standard speed of these characters, although they can increase this speed through their cosmos to the maximum or what could sometimes be described as a miracle in the franchise itself.
Odysseus describes the speed of the Gold Saints as the speed of light.
Cain and Kaiser's blows are described as having the speed of light.
In many fights it is described that the Gold Saints are fighting at the speed of light. In this scene from Assassin, it is described that the speed limit of a Gold Saints is the speed of light (黄金聖闘士の最高速度は光速).
The Gold Saints can exceed that speed, but it's not a regular occurrence and only tends to happen in a few specific moments when they are at the peak of their abilities (sometimes described as a miracle in this franchise).