Nero really wanted to get that innate ability upgrade, but it was a fact that only Arter and Maximilian could provide it to them. If they had unlimited time then Nero would have combed through the Vault looking for it himself, but it was not possible right now. They had barely covered a small portion of this facility that used to house hundreds of workers at one point.
Arter and Maximilian could even tell them that such a procedure was no longer possible since they used up all the supplies, and Nero would have no way of knowing if they were telling the truth or lying.
The truth was that Nero considered coming up with a complicated plan to get them to divulge the details, but such a thing was not something he could execute in their present circumstances, and the chances of failure were high. So he came up with a better, more direct plan.
