After a bit of dramatic mumbling, Timothy finally ordered the system to simply go ahead with this upgrade. And of course that request was instantly obliged.
[Confirmed]
Hilariously, the hero almost always forgot that upgrades tended to come with pain. This was another one of those moments.
He simply did not expect for a sharp pain to strike against his back. But when it did, the darn thing hurt worse than hell and whatever was below that realm.
The hero almost felt like his back had been broken in half, but the actual pain was worse than that.
Because it spread across every other bone in his body, rather than isolating itself on the spine area. The pain weighed pressure on his fins the most, before moving towards his tail.
As for how uncomfortable the process was, well words were capable of describing it.
It felt as if his bones were being pressured from all directions, and he could swear that they were just a flinch away from completely shattering.