There are Nen users who can remove other people's Nen.

A Subterranean Extraction and Removal Combine. It's... automated tunnel boring.

I am currently verifying the checksum and eliminating engram copy errors in the process.

Switched things up on the sly, replacin' the Voodoos' virus with his own brand of rot.

Made a deal with Arasaka, they got the chip out of my head. So go ahead, get pissed if you want to. I already feel like shit.

A compromise. I'll fish the Voodoo virus out of your system. And I'll release both Brigitte and Ti Neptune.

Liquidation terminated. Insufficient resources to continue.

Each is a hundred years old at least. They use spells to erase the years, straighten humps, remove warts and ulcers.