This has to be the hardest plague to beat in mega-brutal

The Necroa Virus is really giving me a hell of a hard time. First off, it isn't easy to spread quickly since you need to save some DNA to evolve the symptom that enables zombies. Second, Z-Com is much more stronger this time and destroying their main base will be hard. Lastly, Genes that stops evolution costs from increasing are removed and replaced by Necro-Virus-exclusive genes.

Several games, several fails. I have yet to win a game. Yeah, that hard for me. I would really appreciate some tips and strategies you guys might have. Expect the guide to take some time before being posted.