OoT Ganondorf was ruined with Demise. Not only was Demise a shame to final bosses worldwide (in my opinion), but his story was about as bad as TP Ganondorf's in all honesty.
The main difference between Ghirahim/Demise and Zant/Ganondorf is that Ghirahim states outright that he is simply a pawn trying to resurrect his master, whereas Ganondorf TP came at a somewhat derp moment. I'll try to compare Demise and TP Ganondorf:
Both have some sort of lacky who is entirely bizarre and utterly useless to the story at the end of it all – Ghirahim : Demise :: Zant : Ganondorf
Ghirahim was far from "utterly useless" at the end of Skyward Sword. He was the actual reason for Demise's return. He wasn't just a pawn like Zant. Zant had nothing until Ganondorf gave him power. Ghirahim already had power to use, making him a legitimate asset to his master. Ghirahim was a huge road block against Link stopping Demise's return. Without Ghirahim, Demise really had no chance of returning. Simple as that. Ganondorf could have found any way possible to get out of the Twilight Realm eventually.
Both are defeated by the same method and make some whack statement that is utterly in vain. I'll elaborate a bit: both are defeated by an Ending Blow (it's awesome!), and then they proceed to stand up, mortally wounded, and shout something as they die. Demise says "blahblahblah my hatred blahblahblah", Ganondorf says "omgzorz blood history....omgzorz". Both are dead, or we can assume as much.
And? Isn't that kind of the point of the whole thing? To defeat the enemy and save the world? That's been the story from the start of the series. Why start complaining now? Just because they both say something doesn't mean anything. That's natural for a villain to do after being defeated. It's not just in Zelda that this happens. You know that, right?
Both appear to be REALLY awesome but that is only a shell to hide their terrible story and character.
Wrong. They had great stories. They just weren't in the game a proper amount of time for them to flesh out, which is a flaw, I'll admit. But they're far from terrible characters. They just had no chance to be.
Both underestimate EVERYTHING IN THEIR VISION. Really, Link has a piece of the Triforce in TP, and he at one point had the entire Triforce in SS.
Gee, I wonder why? Maybe because they've just almost conquered everything and see a 16-17 year-old boy standing in front of them? Would you think such a thing would stand a chance against you? I wouldn't. Especially if I also had a piece of the Triforce. (By the way, the key words of Link and the Triforce in Skyward Swrod are "at one point." He didn't have it at the end, so that argument is useless.)
I don't see Demise and TP Ganondorf as much of a stretch from each other. They both felt like useless villains, because they didn't really do much. We spent the ENTIRE GAME of SS battling Ghirahim and trying to help Zelda. We spent the ENTIRE GAME of TP battling Zant and trying to help Midna. We then get the EXPECTED plot twist of Demise, which in my opinion was pulled off rather weakly, and we get the UNEXPECTED plot twist of Ganondorf, which in my opinion was also pulled off rather weakly. Both were epic in their own right, but that radiance shined for only a slight few seconds, nothing more.
We hardly fought Zant throughout the whole game. He appeared a few times, but he wasn't fought until the end. Both of the "bigger" villains being fought at the end also makes sense. Would it be as big of a battle if they were fought beforehand? No. Ganondorf and Demise were meant only to be the final boss. Having them come back at the end makes sense. Their purpose was not to be the main villain of the game. Zant and Ghirahim were to have that purpose, which Ghirahim pulled off perfectly, unlike Zant. Again, Ghirahim is the reason Demise returned. Without him, Demise had no chance of returning due to Link and Zelda. It's not about any radiance of them. It's just the final threat to stop. Nothing more than that.
Now, to actually answer the question: Demise really did ruin Ganondorf. Why did he have to place a curse? Why? What's the point of that, why couldn't he just outright kill Zelda like a REAL villain would? Why did he have to ruin Ganondorf with his silly statement that means NOTHING AT ALL BECAUSE WE KNOW LINK IS GOING TO WIN?!
The only reason we know Link is going to win is because it's a video game about a hero who saves the world. In reality, Link may not win. He actually has to do something. It's not like he can sit back and expect the bad guys to defeat themselves.
Demise's hatred is a sham. If that is what causes every single villain currently in the Zelda series to do evil things, I'm truly disappointed. "I hate the gods so...yeah, now everyone is corrupt. The end, kthxbai" isn't legitimate...well, it is in a way, but it isn't cool or even EVIL. Nintendo could do better than this. I want an Albert Wesker in the Zelda series; someone who is actually EVIL.
Demise and Ganondorf
are evil. If you can't see that, then that's kind of sad.
Anyway, it's only Ganondorf that's Demise's hatred. Majora was in a different world entirely. Twinrova are Ganondorf's surrogate mothers and are the head of Veran and Onox, who have nothing to do with Ganondorf or Demise (can't be the hatred at the same time). Vaati is under Ganondorf in FSA, so he can't have anything to do with his hatred. It's focused on Ganondorf, but not his origins. Bellum is also in a different world, and Malladus was an ancient demon in another land that has nothing to do with Hyrule. Demise's hate is only focused on why Ganondorf is so evil, as well as why he never stays down. I do agree that it was a bit abrupt with how they "touched on why Ganondorf showed up," but it wasn't the complete failure you make it out to be.
