In the Warhammer Universe of the Main God Space.
Most Space Marines underwent their modification surgeries between the ages of ten and fourteen.
It was best not to exceed fifteen.
Because the gene-seed needed to develop alongside their bodies.
That was when the success rate was highest.
However, the Biochemical Institute's modification surgeries had no such restriction, because they did not rely on gene-seeds.
Naturally, they did not require as long as five years.
Their technology in this regard far surpassed that of the tech-priests in the Warhammer Universe.
According to the estimates of Muzan, Queen, Orochimaru, and the others, completing the full set of modification surgeries would take more than a year but less than two.
If it was only the first-stage modification surgery, the Second Heart,
they could actually be discharged in less than a month.
Besides,
how many people in the Astral Legion could redeem the full set of modifications all at once?
Most would surely redeem their modifications in batches.
Very soon,
under Muzan Kibutsuji's introduction, those inside and outside the venue gradually came to understand the contents of each surgery.
After all, not everyone understood Warhammer or the Astartes.
First stage: Second Heart. Second stage: Bone Reinforcement Organ.
Third stage: Muscle Reinforcement Organ. Fourth stage: Blood Regeneration Organ.
Fifth stage: Regenerative cell Storage Organ. Sixth stage: Neural Knot.
Seventh stage: Pre-Stomach Organ. Eighth stage: Genetic Detection Nerve.
Ninth stage: Multi-Lung. Tenth stage: Visual Control Organ.
Eleventh stage: Auditory Control Organ. Twelfth stage: Suspended Animation Membrane.
Thirteenth stage: Pigment Control Sphere. Fourteenth stage: Pebble Kidney.
Fifteenth stage: Taste Monitoring Nerve. Sixteenth stage: Sweat Gland Enhancement Organ.
Seventeenth stage: Venom Storage Gland. Eighteenth stage: Gene Storage Gland.
Nineteenth stage: Black Carapace.
This one was rather special. When implanted, it looked like an extremely thin sheet of black