Thunderblight Ganon is a boss in Breath of the Wild. It was created by Calamity Ganon to corrupt the Divine Beast Vah Naboris, eventually serving as boss of the dungeon when Link came to free it of Ganon's control 100 years later. If Link doesn't fight Thunderblight Ganon inside of Vah Naboris, he will later encounter the boss in the Sanctum inside of Hyrule Castle.
During the first phase of the battle, it is recommended to stay on the bottom floor where there is the most space to work with. Thunderblight Ganon has two attacks during this initial phase. The first will have him launch some electric balls at you and these can be easily avoided by just moving to the side. Its other attack involves him quickly moving around the room, warping to three spots in a matter of a second, with the third spot being right next to Link. It’ll then deliver a vicious sword slash. The best method to attack him during this phase is to hold out your shield, and just before it’s about to attack you, do a backflip. If you time it right, you can perforce a Flurry Rush. Equip your best two-handed weapon to do the most damage. Repeat this method until half its health is gone.
The second phase of the battle involves Thunderblight Ganon dropping several stakes into the ground and then electrifying them, along with a small area right around them. You want to use your Magnesis ability here. Right when it tosses the stakes into the ground, run away so you aren’t immediately near any of them. Then use your Magnesis to grab one to the stakes before it gets destroyed. Lift it up and push it towards Thunderblight Ganon to cause damage. This is easier to do from a higher elevation as opposed to the ground floor. This phase only lasts one attack.
During the third phase, It is recommended to drop back down to the bottom area. This phase is similar to the first phase, except Thunderblight Ganon is now electrified and hyper-aggressive. If you have a metal shield, be sure to un-equip it. You will want to do a lot of running away during this phase, avoiding at all costs its electric attacks. When it does its warping attack, instead of slashing once, it will slash three times in a row. Thus, if you are perming a backflip to do a Flurry Attack, if you do not time it perfectly, it will almost certainly hit you on its second or third sword slash. When its sword and shield are electrified, I would recommend just running away. Wait until the electricity goes away, and then try to perform a perfect timed Flurry Attack.
When Thunderblight Ganon’s health is low, it will perform a charged laser shot at you. It is advised to avoid trying to do a Perfect Guard of this, instead, just run away. Hide behind a pillar so that the laser does not harm you.