Calamity Ganon is Zelda: Breath of the Wild's final boss. And although anyone can go straight ahead to Hyrule Castle at any time during the game since it's designed for speed runners, defeating Calamity Ganon will be extremely hard without the useful items and finishing the proper quests. Here's a guide on how to defeat the final boss in Zelda: Breath of the Wild.
Zelda: Breath of the Wild And Calamity Ganon
Heading straight for Calamity Ganon even after getting the bare essentials like the Glider will be extremely difficult in Zelda: Breath of the Wild without doing the Divine Beasts quest first. There are Divine Beast dungeons scattered all over Hyrule and four of those are where four bosses can be found mainly Waterblight, Windblight, Fireblight and Thunderblight Ganon. Heading to these dungeons and defeating these bosses one by one before going to Hyrule Castle to defeat Ganon will help Link immensely.
Because without defeating these bosses first, they will be in Hyrule Castle instead to guard Calamity Ganon and Link will have to deal with them consecutively before fighting with the main boss that has been terrorizing Hyrule in Zelda: Breath of the Wild. Not only that, defeating the Divine Beasts first will strip Calamity Ganon down to 50 percent of health when Link goes up against him. The Divine Beasts, however, are also a challenge to kill.
Zelda: Breath of the Wild Calamity Ganon Strategy
If the four Divine Beasts have been defeated, finishing Calamity Ganon off will be easier because of the 50 percent reduction to his health. He will be using similar attacks from his Divine Beast incarnations, and he will also be using weapons that Guardians have used, so it's easy to dodge them when the player knows they're coming and have spent significant amount playing Zelda: Breath of the Wild. The best counter against Calamity Ganon from his attacks, of course, is Flurry Attack, which can be read about from this guide here.
Take note of his attacks, backflip on horizontal sweeps and side hop on vertical slices. Flurry Attacks can deal a lot of damage but the player needs to time it perfectly. It is also important not to be greedy when attacking Ganon in Zelda: Breath of the Wild with Flurry Attack.
Calamity Ganon's second phase in Zelda: Breath of the Wild will start when his health drops to 25 percent. His attacks are similar but with the addition of a very annoying golden shield, which will bounce off any of Link's attacks. Working on breaking through this defense is priority number one. To do this, time his projectiles right (arm cannon or Guardian laser) to parry them and this will bring his defenses down. Be extra careful with parrying the Guardian laser since it will break Link's shield if he misses.
Once Calamity Ganon is dead - surprise! He's alive and will transform into Dark Beast Ganon and Link will be transported outside to Central Hyrule in Zelda: Breath of the Wild. Zelda will give Link the Bow of Light - the weapon that will kill Ganon and it is basically a walk in the park at this point. Just keep circling him on horseback, shooting arrows while dodging his slow attacks.