A full guide on how to beat virus on mega brutal. All you need are the right genes, and it's a piece of cake!
To start off, we will need to insert some genes to increase our chance of victory. The genes I use are catalytic switch, base oxidisation, native biome, extremophile, and translesion +. Now, if you want to use some other genes, you can, it probably won't make too much of a difference and you may be more comfortable with some other genes. However, DO NOT ATTEMPT THIS WITHOUT BASE OXIDISATION. This entire strategy revolves around this one gene, so DO NOT replace it.
Destroying the World
Start in India. Max out viral instability ASAP, then evolve drug resistance 1, cold resistance 1, genetic hardening 1, drug resistance 2, cold resistance 2, then genetic hardening 2. Before you buy something, make sure you will have enough dna to devolve 1 symptom, because the last thing you need is for your disease to become lethal. Now simply save up your dna, you will need it later on. Just watch the world get infected, devolving whatever lethal symptoms your plague develops. Wait until all islands get infected, because if you start killing people before they get infected then you will have to restart. Once all the islands are infected, as long as most other countries are infected, you can now begin to kill people. Purchase total organ failure, and keep the rest of your dna for fighting the cure, as it will go up incredibly fast. Moniter countries that are not fully infected, as you will need to devolve lethal symptoms if the infected population starts to die out. Keep your eye on the cure progress as well, I actually failed when testing this strategy because humans somehow finished the cure before I managed to wipe them out, and 4 people in australia survived. At this point, as long as you have infected everyone, it is just a matter of surviving until you kill everyone. DO NOT WORRY ABOUT SAVING DNA FOR A BETTER SCORE. The SECOND the cure progress hits 95%, evolve genetic reshuffle or a symptom that decreases the cure progress. Follow this, and you will most likely win.