From Guild Wars 2 Wiki
“Become a virulent cloud and inflict multiple conditions on foes you touch. Entering this form destroys all minions and removes other spectral effects.
— In-game description [?]
 Description and skills
Plague transforms the user into a plague, with three different skills replacing the standard weapon skills.
|Withering Plague||Add bleeding to your plague.|
|Plague of Darkness||Add blindness to your plague.|
|Plague of Pestilence||Add cripple and weakness to your plague.|
- The first 3 skills on your skill bar will change while in this form, whereas the last 7 skills are locked for the full duration.
- Plague also grants stability for the duration.
- While in Plague form, the necromancer's base power is doubled, base toughness quadrupled, and base vitality tripled. At level 80, this adds 916 power, 2748 toughness, and 1832 vitality.
- Plague attacks automatically. By default it only poisons, but by hitting one of the skill keys, that Condition is added to the automatic ticks. The skill buttons need not be spammed.
- Only one of the three abilities can be active at a time, using a new one will replace the old.
- The radius indicator is smaller for Asura, the effect area is the same for all races despite this.