Saint Seiya Omega/Headscratchers

Losing 5 Senses = Being counted as useless/unactive for combat; since when?
It seems Omega's writing staff simply do not know how Saints and their senses work, or They Just Didn't Care. It was always commented upon that Cosmo energy is basically the 6th, 7th and 8th senses, the first five is not important to a true Cosmo enlightened Saint, in fact, that's how Ikki achieved his 7th sense by having Shaka block all of his 5 others. In Omega we have Shiryu, a Saint of Legend as the series describe him and his friends, who apparently lost his 5 senses in battle, possibly against Mars, and the series treats him as if he became a vegetable. Shiryu can't see, can't feel, can't smell, can't hear, can't talk/taste, that's really bad, but that doesn't imply he can't move thus still being able to fight like usual, he should actually be stronger if any else by having those "five hindrances" removed; in short terms, I can't see how losing 5 senses makes him a cripple in his world.
 * I don't think anybody said Shiryu was useless or unable to fight. Quite the contrary, it was stated that, even without five of his senses, he was still competent enough to train his son, and is able to communicate via Cosmo just fine. Ryuho wants to help his father because missing 5 senses sucks even if you are a Saint, not because Shiryu is helpless without them.