Ganondorf Dragmire (also known as Ganon in his beast form) is the main antagonist of Zelda franchise. He is a power-hungry man who wants to rule over Hyrule and make it a dark place filled of monsters. In most of the games he is called with the title of Demon King: however, he is the reincarnation of another Demon King, the source of all evil himself: Demise. Demise was an extremly evil and ruthless demon who wanted to cover the world with his monsters and destroy humanity: he was extremly powerful, and after his defeat, he cursed everyone who had the blood of the goddes and the soul of the hero. That's how Ganondorf was born. What makes Ganondorf complex is the fact that every single incarnation has a different personity, and just one incarnation is as evil as Demise.
Overall, every single incarnation share the desire to rule over Hyrule, but they're so different, let's give a moral rank to everyone of them:
-Ocarina of Time: The first incarnation we know, and probably the most important one. This one is a completely ruthless and violent man, he's pretty good in tricking and manipulating his enemies: he pretended to swear loyalty to the king, just to betray him, enter the sacred real and steal the triforce: however he got just one piece. He took over the kingdom and brought enormous disasters: he froze the zora village, he trapped the gorons to feed them to a dragon, he sent his monsters to the forest amd a lot more. However he still respected the Gerudo, his tribe. That makes him a Near Pure Evil.
-Wind Waker: This one is his most tragic incarnation: he still remembers what happened in Ocarina of Time and feels like a broken man. He still complains how bad was for him and the Gerudo living in the desert, where the wind brought only death. He spares Link and Zelda multiple times and has a lot of sympathetic moments. He's Inconsistently Heinous.
-Twilight Princess: Well he's basically the same person we see in Ocarina, this time Link told Zelda the truth about him before he could trick the king. The sages fail to kill him once and for all and they have to send him into the Twilight Realm, where he meets Zant, another power-humgry guy, and uses him as a pawn in order to return to Hyrule, making him indirectly responsable for all the bad actions Zant has done. After he's revived and Zant is dead, he refuses to revive him. While we don't see his "good side" because there is no other Gerudo in this game, he's still the same person he was in Ocarina, so he's Near Pure Evil.
-A Link to the Past: Kinda the same thing of Twilight: however, this time he won, he killed Link, he remains in his beast form, but he was sealed into the Sacred Realm, now turned into the Dark Realm. He uses his alter-ego Agahnim to trick the Royal Family, acces to the castle and kill the King, so he can manipulate the Kingdom.by himself. Again, he's Near Pure Evil.
-Oracle, A Link Between Worlds, Classic Zelda: He's basically a mindless monster, so they're Inconsistently Heinous.
-Breath of the Wild: Here he's known as Calamity Ganon, and again he's a mindless beast, so he's Inconsistently heinous, but...
-Tears of the Kingdom: ... the Calamity was just a portion of the Ganondorf in this game, it was just a big quantity of malice that came out of his body and created that monster, but what we have here is way worse. This Ganondorf is definitely as bad as Demise, if not even worse. He totally lacks any good traits all his other incarnations (and even Demise) had. He played a similar game thet his Ocarina of Time counter part played with the king, however this time the king immediatly noticed that Ganondorf was a bad guy, yet even that was part of his plan. He murdered queen Soniah to get the secret stone for him and immediately created a massive army of monsters, he even turned against his own people. He's also indirectly responsable for all the deaths amd destruction the Calamity has caused. And centuries later, when he came back, and caused a lot more troubles, when he was about to be defeated by Link, he decided to turn himself into a mindless dragon to kill Link and cast the world into eternal darkness. That said, he's definitely Pure Evil