|“||That...is Calamity Ganon. One hundred years ago, that vile entity brought the kingdom of Hyrule to ruin.||„|
|~ Zelda on Calamity Ganon.|
The Calamity Ganon is the main antagonist of the game Legend of Zelda: Breath of the Wild and likely it's sequel. He is another reincarnation of Ganondorf. In that game, all three timelines of the Zelda franchise supposedly unify again. The Calamity Ganon took over Hyrule Castle and brought terror to the land for 100 years, trapping the princess inside the castle.
While Ganon was always was depicted as demonic and frightening, he is there portrayed as a titanic mass of black and purple dark Malice, constantly swirling and distorting, shaping itself as a boar's head with glowing yellow eyes, gigantic tusks and an expansible mouth. This seems to be a premature form of his true Beast appearance, which is that of a gigantic purple boar with glowing eyes and a flaming mane.
When he tried to manifest into a physical body he looks like a deformed spider-like abomination. His flesh is made out of malice, but he's also partially made of Sheika gear and has their weapons attached to his limbs. He has a humanoid skull with glowing orange eyes and a long beard and mane of wild, red hair, remnants of its existence as Ganondorf.
His true body is that of a gerudo man with long red hair. It is simply a corpse which has almost completely rotten away. He still wears some gerudo armor and accessories.
The Calamity first appeared 10'000 years ago, where it attempted to destroy the land of Hyrule. But together with all the Sheikah technology, the princess and her knight were able to defeat it and seal it away under Hyrule Castle. There it was trapped for a very long time. Presumably that what they trapped there, was Ganondorf's corpse.
However, 100 years ago it started leaking Malice, a viral life form that is basically Evil in physical form, which started to spread in the land. The royal family noticed and prepared for the new reincarnation and trained special Champions of each race to pilot the huge Divine Beasts, four gigantic, animal-shaped, magic-powered warships.. Together with an army of powerful, mechanical Guardians, built by the Sheikah for his inevitable return, they should have been able to defeat the Calamity once again. But Zelda wasn't sufficiently prepared and hadn't awakened her sacred powers. So when Ganon emerged, they weren't fully prepared yet. His essence resurfaced and he caught the Champions off guard.
He used his Malice to take control of all the Guardians and used them to destroy the entirety of Castle Town and taking over the castle, slaughtering everyone present, including the king. The Champions were also subsequently killed and he took over their Divine Beasts and implanted a Blight Ganon in each of them. These machines were used to unleash even more destruction and also caused terror for the near settlements. His arrival also surfaced the Yiga Clan. They were Sheikah who betrayed their tribe and started to worship Ganon. Link and Zelda were running away and fighting their way through Guardians who were destroying everything in their path. But Link got fataly injured and Zelda was in tears. She blamed herself for everything, since she didn't get a hold of her divine powers. But through all the suffering around her, she finally found the strength to awaken her power.
She sent Link to the Resurrection Shrine and went to face Ganon alone. He, after destroying many towns and killing countless people by spreading his army of Guardians and monsters, planned to materialize fully. But Zelda stopped him and managed to bind Ganon to Hyrule Castle. She keeps him confined, but has to use all her strength to do so. Zelda endured fighting with Ganon for 100 years, giving it her all to seal him, while he tried relentlessly to break free of her binds.
The whole thing was a cataclysmic event, so that even 100 years later, most of the kingdom is still reduced to ruins overcome by wilderness, and civilization has heavily regressed, safe for a few settlements. Calamity Ganon is sealed but the Blights are still controlling the Divine Beasts to lay waste on the land, weakening the seal that is about to break anytime soon. Despite being sealed, he still spread his Malice over the the entire country, corrupting the land and spawning many monsters. He covered numerous structures, where it festered and destroyed them along with the nature around it. Hyrule Castle is covered in the most Malice, as this is where it stemmed from. Every now and then, a Blood moon appears. At this time, Ganon's powers momentarily increase and he is able to revive all the monsters who were previously killed.
Breath of the Wild
Link awakens again having lost all his memories. Zelda calls out to him and tells him of Calamity Ganon. He is hovering around Hyrule Castle, where he is still confined, clouding it in a dark mist of Malice. He stays there, while Link journeys around the land. He doesn't interfere directly, but always reminds Link of what he must do. In general, he causes a dark presence, that lurks in every corner of the land. Link frees the Divine Beasts and the spirits of the Champions by defeating Ganon's Blights. He then makes his way to the castle and after battling many more monsters, the Hero of Hyrule finally reaches the throne room.
There Ganon lurks within a giant cocoon, that resembles a human heart, attempting to regain his physical form. But Link interrupted him and since Zelda was at the end of her strength, he broke free and regenerated prematurely, leading to him looking monstrous and messy as he was still not complete. The Divine Beasts, whose pilots were rescued, then fired their cannons in his direction, severly weakening him already. Ganon was full of hatred and anger and attacked Link with all weapons he had in his possession. He crawled on the walls and uses many elemental attacks, that the Blights have used. When he is weakened even further, he created a force field around his body that would protect him, but Link bypasses it by reflecting Ganon's laser back at him.
So Calamity Ganon was ultimately defeated. He let out a monstrous roar as his body violently disintegrates and his spirit summoned all the Malice in the kingdom to him and manifested into his true Dark Beast form. Zelda said that the Calamity Ganon had given up on reincarnation and assumed his pure enraged form. He stood in the middle of Hyrule Field and shot giant beams of dark light at Link. Zelda aided the famous Hero of Time and opened up weak points where Link could shoot arrows of light. As Link did so, the Calamity Ganon lost more of his power. Eventually his core was revealed and Link shot one final arrow into the giant pulsating eyeball. Zelda emerged from within him and she used all her power to seal him again, bringing the land back to peace.
Breath of the Wild 2
Zelda and Link find the corpse of Ganondorf, whose Malice is still leaking out of his body. The power of his Malice seems to grow and manifest once again and his eyes glow up, indicating he might come to life again.
The Calamity Ganon differs from Ganondorf quite a lot. He appears as a mindless monster who only wants to cause destruction and suffering. Ganon is actually referred to as an "it", for, without a proper incarnation, he is but a manifestation of absolute evil and hatred, a barely sentient entity. There is nothing left of his intelligent and cunning side Ganondorf, which implies Ganon to have become completely insane. Despite this, the Calamity is still immensly powerful, as killing the champions was easy for him. Had they managed to spread unchecked, he and his minions could have gone to and destroyed some other planets.
- The english version states, that Ganon assumed his Beast form, since he gave up on reincarnation and simply wanted to manifest and cause destruction. In the Japanese version, however the exact opposite was stated, in that Ganon assumed this form specifically because he refused to give up on reincarnating himself.