Vampirism (Online)

Vampirism is a disease in  that has various effects on the character's appearance, resistances and even adds a new skill tree. It has four stages of severity, with every stage making the negative effects stronger but also reducing the cost of vampiric abilities. Stage one is the least severe one and four the most severe. Over time vampirism progresses to higher levels, and feeding on NPCs or other players resets vampirism to stage one.

Getting infected
The player can get infected with vampirism by getting attacked by an NPC vampire, or by being fed on by another player who is afflicted with vampirism. Any player with lycanthropy is immune to vampirism and vice versa.

Negative Effects
Every vampire has a 40% weakness to fire damage and regenerates health more slowly than as a humanoid. While the 40% fire weakness is the same at all stages, the health regeneration penalty grows bigger with every stage towards stage four.

Vampire skill tree
Ultimate ability: Active abilities: Passive abilities:
 * Bat Swarm  (surrounds the caster with a swarm of bats, deals magic damage to nearby enemies for the duration)
 * Drain Essence (drains target's magicka and turns it to health and stamina for the caster)
 * Mist Form (take 75% less damage, immunity to healing magic & control abilities)
 * Savage Feeding (feeding stuns the victim for a couple of seconds)
 * Supernatural Recovery (increases magicka and stamina recovery)
 * Blood Ritual (allows the player to turn other players into vampires every 7 days)
 * Undeath (increases damage mitigation when under 30% health)
 * Unnatural Resistance (health recovery increased in vampirism stages 2 through 4)
 * Dark Stalker (increases movement speed while sneaking, entering sneak is faster at night)