Vah Rudania, Divine Beast of Fire
Go down the stairs in the dark, then shoot an arrow at the two eyes and at the one on the ceiling. Open the first chest which contains a Dragonbone Boko Club, the second one a long-lasting torch, and the other one close by for some Ice Arrows. Get near the blue flames, light your torch, then look for a lantern on the other side of the room and put it on fire, which opens a door. Get rid of the Guardian, then shoot an arrow at the two eyes on your left. Open the chest further which contains a Knight's Bow and put another lantern nearby on fire. Then get rid of the two eyes on your right, which makes two chests fall down that contain some Wooden Arrows. Light your torch again and go ahead into the next room. Look for the Guidance Stone and look at it to get the map of the Divine Beast. You hear Daruk's voice again telling you to activate all the control panels marked on the map. Then, some panels open and the light enters the Beast.
In this temple, you have to be a good spotter, because it's not easy to find your way. Go back into the hall, put the vines on the great doors on fire (thanks to the blue flame or with a Fire Arrow), then open these doors with the Magnesis Rune. Go ahead and look at the first control terminal to activate it. Then shoot a Fire Arrow at the vines on the ceiling, and pick up an Ancient Gear in the chest which fell down. Go back into the hall, climb the slope to get out and go straight ahead to the end of the tail to grab an Ancient Screw from the chest. Then, backtrack and climb on the Beast's back where the main terminal is. Just a bit further, shoot at two eyes up (one on each side of the Beast) to destroy the pink substance.
Look down, through the openings and locate a diagonal path. Jump on it and open the chest for another Knight's Bow. Then look to the right, there is a control terminal turned of a quarter turn. Look at your map, rotate the Beast of a quarter turn, then immediatly take out your Paraglider and fly towards this terminal. Activate it, then rotate the Beast again. Go back into the hall and look through the door in which there is a hole. Dip an arrow into the blue flame and light the lantern on the other side of the door. Get in, then put the vines on the ceiling on fire. A magnetic bloc falls down. Use the Magnesis Rune to place it against the flames, then look at the map. Rotate the Beast of a quarter turn, the flames are now horizontal. Place the block on the side where the flames are coming out to block them, then go behind the cube. Rotate the Beast again, then go to the control terminal and activate it.
Go back into the hall, dip your torch into a blue flame then stand next to the wall facing the big metallic doors, under a big transversal beam (a chest should have slipped over there). Rotate the Beast (with the pink dot at the bottom), then climb along this metallic beam leading outside. Outside, turn left and carefully go down. Put another lantern on fire, which opens a hatch. (Do NOT go to the chest for now.) Rotate the temple again, then a ball goes down a corridor. Follow the ball, get rid of the skull, then rotate Rudania again. Go down the slope until you reach the ball, then use Magnesis to lift the cube and make the ball fall down into the container below. Jump down, and if the ball isn't into the container, place it in it. Activate another control terminal, only one left!
Place the Beast back into its horizontal position, then stand under the transversal beam and rotate once more. Climb the slope again, go down along Rudania's body again, then this time, carefully go to the left, up to a chest containing an Ancient Core. Then, turn around and stand right in front of the small wall (that you can't climb back). Rotate the temple one last time, then look to the left and go towards the last control terminal. Activate it, then Daruk tells you to go to the main control unit. Use the Paraglider to go down a level and reach this terminal. Place the Sheikah Slate on it and then Fireblight Ganon appears!
During the first phase, you mostly have to avoid his big sword blows by doing side jumps or backflips, then as soon as you can, shoot two or three arrows (ice arrows if you have) at his blue eye. When he's injured, he leans back, dash at him and give him as many sword blows as you can (and with your strongest weapon). Repeat this a few times while not going too far from the control unit. When he has lost over half of his health, the second phase begins.
Fireblight Ganon protects himself within a fire barrier and throws fireballs at you. Avoid his attacks by taking cover behind a stone pillar or the control unit, then as soon as he inhales some air, throw a bomb at him and make it explode. If he's hit, dash at him again and strike him as much as you can. Afterwards his barrier disappears and you can shoot ice arrows again. Repeat these steps to defeat him.
Then, take your well-deserved Heart Container, then get close to the terminal. If you think you've found everything inside the Beast, activate it. Daruk then appears and thanks you for freeing his soul. He entrusts you with his power, Daruk's Protection.
You end up at the entrance of Goron City. Talk to Yunobo who thanks you for calming Rudania down and tells you to go see the boss. Go see Bludo and talk to him, then he gives you his treasure which used to belong to Daruk. Get into his house and open the chest on his throne which contains a Boulder Breaker.