Seized Construct

is a TotK: in.

Characteristics
The Seized Construct is a large humanoid Construct similar to the Construct built by Mineru to house her spirit, and according to her it was a prototype of her Construct body. It has since been stolen by Ganondorf to stop Mineru from reclaiming her TotK: and now visibly emanates TotK:. It is fought In the Spirit Temple or by Link in Gloom's Lair if it is not already defeated.

Unlike the other Main Quest bosses, the Seized Construct cannot be re-fought in the Depths after defeating it.

Battle
Attempting to fight the Seized Construct directly is all but pointless- it possesses an enormous amount of health and takes no damage from arrows if they have not been fused with explosive items. Furthermore, the entirety of the arena's floor is covered in Gloom that will inevitably drain all of Link's hearts.

Instead, Link must pilot Mineru's Construct and knock the Seized Construct into the electric fences surrounding the arena. Several Spiked Balls and Cannons, as well as any Zonai Devices Link might have in his inventory, can be attached to the construct's arms to enable it to attack at close quarters or long range. The Construct will similarly try to push Link and Mineru into the fence, and so they should wait for it to attempt an attack before closing in and retaliating.

Upon losing half its health, the Seized Construct will grow two additional arms; it will also attach a Rocket to its back, two Fans to its lower arms, and two Cannons to its upper arms. It will immediately follow up by flying into the air before firing repeatedly. Link and Mineru can either focus on defending themselves until the Seized Construct lands, or counterattack with Cannon fire of their own. The Seized Construct will also attempt flying body slams, which will deal significant damage but can be baited in order to create further opportunities to knock it into the electric fence.

Trivia

 * The Seized Construct is one of two bosses whose HP doesn't change based on story progression, having 20,000 HP regardless of when it's battled.