The other watches the procedures silently.
It is a Scout. It watches, it travels swiftly. When necessary, it charges artillery formations like it's in the Light Brigade.
But it doesn't talk. It doesn't even comment on the proceedings nonverbally by hissing or tapping its clawtips. It observes the surgeries.
There's an idea that occurs to them later. Not to the scout or the queen watching through it, but to others in the hive mind remembering this later. Tauron looks like a sculptor working on their body.

That amazing strength behooves Tauron to carry out his surgeries quickly, lest the incisions heal before his eyes without the new components having been installed.
But it also makes things easier in a lot of ways. What would be a lethal strain on most creatures' systems is...not.

Fay lays on the surgical table, convalescing.
The brain slowly begins to integrate all the new nerve pathways and signals. The new mechanical legs (useful for supporting all this metal, I imagine) connect. All this half-living metalloplastic is flooded with zerg microbes and muk, adapting, absorbing, unifying this new flesh with the whole. Likewise, the dark fluid suffuses the original body, the different transformative forces mingling and recombining.

Time goes by. Perhaps Tauron will see to to some of those alerts in the meantime. Until eventually Fay wakes, regenerated into this new form. They start to sit up - clumsy, unused to their body - but then pause and mostly just look at the new body through the scout's eyes.
Barely recognizable.
Bigger, probably. You can't add on four layers and a pair of limbs without bulking up a bit. But smooth, streamlined. All the armor's on the inside again; they're a consistent purple (with a little of Fay's own orange tone showing through). The same sweeping antennae, but thicker, sealed in that black carapace. Like the queen's. The jaw meet neatly in the middle, the teeth all fit in the mouth - their throat still aches. Trying to speak, they manage only a wordless mumble. But it's a voice. Pronunciation will come in time. The wings spread - purple panels, orange spans - are those membranes skin or plastic? Wrong question, asking 'or'.

It seems the procedure worked.
But - do those electronics do anything unexpected, any more than making this all work?
Will such dramatic changes have any effect on how one thinks?