Continuity mistake: Seiya creates a large crater in the arena, deep enough that he has to step out of it to offer his handshake to his adversary. Cassios refuses the handshake and kicks him, making Seiya jump away. He then charges at Seiya in a straight line, as if the crater didn't exist, but when Shaina screams at him telling him to get out of the way, Cassios is exactly on the edge of the massive hole. It's as if he walked on air during his charge. (00:06:20)
Der Kampf gegen den Drachen - S1-E3
Plot hole: Shiryu states that the Dragon Cloth, which has been 'for eons' under the waterfall (let's just say it's an exaggeration) is harder than diamond and invulnerable to any attack. In the original manga and anime series, Pegasus uses a sudden dodge during a daring grapple to get Shiryu to strike his own shield with the glove of the armor, shattering both ("invincible sword meets invincible shield") and causing him to fight barechested. In this remake, this whole part does not happen, so when Seiya wins the fight with a heart punch like in the other versions, he does it when Shiryu has his heart still covered by the thick breastplate of the armor, making the whole "Shiryu's armor is impervious to any hit and much stronger than any other Cloth" plot point completely moot.
Suggested correction: It is only said that the "Dragon Shield" is unbreakable.
No, says much more than that. "That might be true for other armors, but the Dragon Armor is special. Nothing can get past my shield. It's unbeatable. The day my Cosmo forced the waters of the Lushan to flow upwards, it revealed the Dragon Armor. Battered for eons by the falling water, the Armor had grown harder and more radiant than a diamond. My Armor is the hardest substance known to man. No matter how fast or hard you strike, you've lost, Seiya." He parried the blow with the shield and so that deserves a special mention, but they keep mentioning the armor as having intrinsic properties, and he is wearing the armor when he is struck by Seiya, which guards his heart. In the original anime and the manga he was armorless after Seiya wrecked it, in here it's intact. It makes no sense, which is why I categorize it as a plot hole and not just as Character error: it's not that maybe he's wrong about the armor, it's the whole situation that now is flawed reprising the original with key differences.
Character mistake: Shaun says that the underground facility is "built like a bunker", but the single missile they dodged just created a huge hole a moment earlier. (00:11:40)
Other mistake: When Seiya blasts with his special move the helicopter, causes an explosion, but there's no damage on the vehicle nor smoke, fire or any sign of what he has done when we see it spin and eventually crash-land. (00:13:50)
Continuity mistake: Shiryu puts the medal on Seiya's chest (no idea where he found the string to craft a necklace with that). Pegasus coughs and the medal shifts a little, but not by much. The three remaining knights talk and vow to get the armor back while they leave the moribund lying there. He does not move during that, and yet when they take off the dog tag moved more to the left. (00:16:55)
Other mistake: When Shaun KOs the first Black Knight with her chain, the other two Bronze knights are at distance from the enemies. However, they are quite literally at their feet a moment after - and they got there by crawling, even. (00:20:00)
Der Aufstieg des Phoenix - S1-E6
Continuity mistake: During Nero's flashback, the right half of his head and most of his body are into the shadow after he gets hit by his sensei, but fully sunlit when the camera is behind the brute. (00:06:00)