The Great Sky Island in The Legend of Zelda: Tears of the Kingdom might not be as big as the game's major world, but it is still big enough to explore every corner and fight off an optional boss.
During your exploration of Temple of Time's floating area, you may have come across a round platform with a watch tower in the middle. This is the location of Flux Construct 1, but unlike the appearance, the boss is not a watch tower at all.
Updated by Mehrdad Khayyat on July 11, 2023: This article now includes extra links to guides that provide more in-depth insight into some of the terms used here for beginners, including one that lets you learn the basics for the Ultrahand ability in the game.
How To Get To Flux's Location
There are a bunch of ways to get to the location of the boss, but probably the most basic method that is available for almost all players is to make a bridge using logs. The Location of the Flux is shown with red circles on the map above. The small red line, however, showcases the bridge that you need to put on the platform in the south of the Flux's location. Hopefully, you can find plenty of trees to cut down in that location.
You need to attach at least 6 logs using Ultrahand to make a bridge that covers the gap between the two floating platforms, but we connected 7 logs to make it safer. Put down the log bridge similar to the image above and use it to move towards the watch tower.
How To Beat Flux Construct 1
Once the watch tower spots you, it will change its form and turn into a block-made robot. If you look precisely, the block on the left hand of the robot has a different appearance, which is your target block. That is the only weakness of the robot and the only block that you can deal damage to.
No matter how far you are standing from the robot, it will perform a smash attack, but just before smashing, the robot will keep its hands over your head for a few seconds; you need to run away at this moment to avoid the smash. Once the robot's smash hits the ground, return and deal as much damage as you can to the target block. After the first hit, the robot gets exhausted, and if you continue to hit with a powerful weapon, you can finish the first phase, resulting in a form break for the boss.
When the robot form breaks, all blocks scatter around, giving you an even better opportunity to deal damage to the target block before the second form shapes, which is a giant cube. This is the easiest part of the fight. The cube will roll toward you, but you can easily avoid it by running. While you can deal damage to the target block using arrows, the Ultrahand ability is a much better tool here.
In order to break this form, you should either pull out enough blocks from the giant cube that it loses its form and scatters around, or you should simply grab the target cube with Ultrahand and pull it toward yourself to break the form, resulting in another damage phase for you to beat the block with a melee weapon.
The third form of the Flux Contruct 1 is a floating surface that throws blocks at you within a certain period. Similar to the latest phase, you can still use a bow and arrow to damage the target block, but the best way is to get beneath the surface and grab the target block with Ultrahand. Now, pull it toward yourself to break the form and deal damage.
In the final phase, the Flux will turn into a robot once again, but this time around, the target block is placed on the left shoulder of the robot. In order to finish the battle, you are advised to wait for the robot's smash, and when it hits the ground, run to the left side of the robot and activate Ultrahand to grab the target block and pull it out. If Flux is too low on the health bar, you can simply shoot arrows to defeat it.
Once the Flux is defeated, it leaves a bunch of Zonai Charges as well as Zonai Capsules as loot. The core of the target block also drops, but you can't collect it. That being said, you can move the core using the Ultrahand ability. You can use the Fusion ability to attach the core to a weapon and enhance it significantly.
