I just played through, and at the ending where you have the choice to die for everyone or send Lyons in, I went in and activated the purifier. But at the end, it gave me the bad ending saying I chose to not sacrifice myself. :banghead:

Why would it do that? I had good karma whole game, only thing I can think of was I put the modified FEV into the purifier, but still sacrificed myself so I don't get it.

Also I hear if you put the modified FEV in, you get negative karma in the DLCs. How come? I thought it was supposed to be harmless to normal humans, only damaging to mutated.

It's because you decided to fall in-line with the Enclave's evil plan of mass murder. It isn't just Ghouls and Super Mutants that die, it is nearly everyone who lives on the surface outside of a vault exposed to the FEV and radiation.

He tricked me! :brokencomputer:

No he didn't the only trick is him saying your probably immune because you grew up in a vault. But then Eden has no way of knowing you were actually born in the wasteland.