What about patrice and Varimathras, the great pharmacists of WLK Royal Pharmacists Association?

Patrice, a great pharmacist, played a very important role in the second natural disaster invasion (CWOW had no experience, which was a tragedy). His research results can resist the plague of the undead and even "cure" it. This epoch-making research directly promoted his position from "chief pharmacist" to "big pharmacist" (there are only two places in the whole Royal Association of Pharmacists. Dr. Sintar Melfis Dr. Sintar Malifios, another great pharmacist, was stationed at the outpost of the Forgotten (Northrend).

After the second natural disaster invasion (TBC is coming to an end), players set foot on Northrend's frozen soil (WLK is opened) and helped the Royal Pharmacists Association to develop this new plague in the forsaken outpost, named "The Desolation of the Forgotten". The development of the plague was very successful, and players immediately experienced its power in the Anger Gate incident.

Varimathras, the demon of fear who secretly betrayed Queen Severus, is actually still loyal to his Nasrem brothers and its birthplace: the Burning Legion (another doubt is explained here, who encouraged the demon of fear to defect). Varimathras and patrice staged a coup together, took control of undercity and "almost" killed the Queen. Although the coup was ended by the tribes and alliances that arrived later, the problem of the Anger Gate was finally solved.