I'm at the same point. The Tchort battle is looking really tough, I've done a few exploratory attempts on him, it seems like I might be able to do it but it's gonna be a slog. (I did manage to bumrush the big guy and use Thermionic Destabilization followed by Proxy'd Implosion and Punch on a tentacle to put even mighty Tchort down to like 1/2 health, but I couldn't sustainably deal 200 damage/turn to keep that run going.) I'd like to try to figure out how to run the mutagens, but I'm at a loss.
My mutagens:
Echo 1-4, Helicon 1-3, Io 1-3, Ovid 1-3, Solis 1-2, and Exitus-1. I've quite thoroughly searched the DC, so I don't think I missed any mutagens, unless they're behind very difficult hacking or lockpicking challenges (>120 lock, >130 hack).
I haven't read a good description of the various mutagens, all I recall is a conversation in the housing area where mutagen compounds only include positive atoms, and one positive at most, and reagents have negative atoms that cancel out positive atoms. I guess I could start recording each mutagen's actions and interactions, but that seems like it's gonna be a really long project.