The Plague Chalice

Mark of Nurgle only. The Shaman may drink from the Plague Chalice at the start of his Magic phase. He suffers an immediate S 4 hit that ignores Armour and Ward saves. For the remainder of that Magic phase, any spell casting attempt by the Shaman that includes any double (except 1's) on the initial roll gives the caster another free power dice to the casting attempt.