How to defeat Flux Construct I in Tears of the Kingdom
As you explore the Garden of Time at the start of The Legend of Zelda: Tears of the Kingdom, you will likely notice a giant circular platform with a stack of blocks on it, with one of them emitting a red searchlight. These blocks, which come to life and form various shapes to attack Link when he gets close, collectively go by the name Flux Construct I. In all likelihood, Flux Construct I will serve as the first overworld miniboss you encounter in Tears of the Kingdom. You can reach the arena it resides on simply by moving a floating platform between it and the nearby cliffside and jumping across.
Throughout the fight, the blocks that make up Flux Construct I will shapeshift into three different forms. Each one comes with its own quirks and attacks, so you will have to approach each one slightly differently.
Flux Construct I will always start out in the shape of a humanoid, which will usually attack by slamming its fist on the ground when you’re at a distance. From my experience, trying to sidestep this attack and trigger a flurry rush did not work. In fact, the sidestep hindered me more than it helped in this instance, as the shockwave that the fist emits on impact would usually send me flying, regardless of if I had my shield out. Generally, simply sprinting away from the attack will serve as your best strategy.
Once the boss slams its fist down, it will leave it there for a good while, providing a window of opportunity for a counterattack. The sole glowing cube on its body functions as its core and weak point, and its location will be randomized every time. Sometimes, the boss will set the glowing cube on its fist, making it easy to target after the slam attack. Other times, the cube will be situated on one of its feet. Hitting the glowing cube with an arrow will temporarily stun the boss, but if you land several melee attacks or arrows in succession, all of the cubes will scatter, leaving the weak point vulnerable for longer.
This phase is at its trickiest when the boss puts the glowing cube on its back, making it difficult to target with arrows. Fortunately, your Ultrahand ability can freely remove any one of the blocks from its body, making it easier to see the glowing block and land shots on it. You can even use Ultrahand on the glowing cube itself. Once you grab onto it and shake it loose with the right stick, the blocks will scatter instantly, which is much more efficient than doing the same with your weapons.
Screenshot via PC Invasion
After the blocks scatter and you wail on the glowing cube for a bit, the boss has a chance of reforming into a larger cube, which will tilt around and land on its sides in an attempt to crush you. Normally, you can simply wait for the glowing cube to become level with the ground and attack it with melee weapons without taking too long and letting the boss crush you.
However, you can simply stand at a distance and scatter the cubes using your arrows or the aforementioned Ultrahand strategy. And because this form doesn't move very fast and solely attacks in close quarters, you will practically never get hit if you do this. For this reason, I found the cube phase to be by far the easiest of the bunch.
Flux Construct I also has the chance of transforming into some kind of flat rectangular shape that stays suspended in the air. In this phase, you can always see the glowing cube from underneath, so simply walk close to it and use Ultrahand to shake it loose.
However, you need to stay careful in this phase, as the boss will send a row of blocks sliding toward you on occasion. Slipping between the blocks will be enough to keep you safe, but they deal quite a bit of damage if they hit you. If you don't stay topped up with food, you can easily get killed by this attack, which I learned the hard way.
Just like with other overworld minibosses in these more recent Zelda games, beating Flux Construct I in Tears of the Kingdom will mostly reward you with materials. In this case, the boss will leave behind Zonai-related materials, including Zonai Charges that can help keep your Energy Cell battery topped up when using Zonai devices. Additionally, the boss will drop its spiky, cylindrical core, which you can't pick up by yourself. However, if you fuse it with one of your weapons, it will augment it with a nice, hefty attack boost.
Screenshot via PC Invasion
You don't have to defeat it to progress in the main quest, and you can always come back to it later if you don't feel equipped to fight it yet. Fortunately, if you do choose to take it on early, it is more than beatable even with your low-level gear and hearts.