Looking over my analytics tonight I saw that a few people arrived on this site after asking Google the question, “will necrotic plague still be in Legion?” The short answer to this question is no, necrotic plague is not available to Death Knights in Legion. As of writing this each Death Knight specialization has one disease each, Blood Plague, Frost Fever and Virulent Plague. No prizes for guessing which disease belongs to which specialization.
For Unholy Death Knights you’ll want to grow accustomed to Virulent Plague. Virulent Plague is applied by what will be a retooled Outbreak. With Blood Boil removed from the Unholy tool kit in Legion, Unholy Death Knights will be relying on Outbreak to, not only get Virulent Plague up on a target, but also to spread it.
Outbreak: Deals (38% of Attack power) Shadow damage and surrounds the target in a miasma lasting for 6 sec that causes the target and all nearby enemies to be infected with Virulent Plague.
I’ve played around on the PTR and spent a little time in Endless Proving Grounds to test things out but haven’t figured out exactly what radius applies to the ‘all nearby enemies’ aspect of the tooltip. Virulent Plague itself picks up an element of Wandering Plague, the Unholy effect from the current Death Knight class trinket.
Virulent Plague: A disease that deals [7 * (42% of Attack power)] Shadow damage over 21 sec. It erupts when the infected target dies, dealing (100% of Attack power) Shadow damage divided among nearby enemies, and has a 30% chance to erupt each time it deals damage.
This is all PTR/Beta information so values and details may change between now and launch.
So for anyone wondering if Death Knights will have Necrotic Plague in Legion? Short answer is no. As of right now, the only way a Death Knight will have Necrotic Plague in Legion is if they travel to the top of Icecrown Citadel and visit our old mate the Lich King.