Auras and Heralds The Help Panel
Auras and Heralds
Auras are skills that persistently affect things around you. Most auras, such as 'Hatred', affect you and your nearby allies and party members. They usually grant some sort of benefit, but reserve a portion of your mana for as long as you keep them activated.
Some auras instead affect your nearby enemies. The 'Blasphemy Support' turns any supported curse into an aura that reserves some mana and curses any enemy that enters its radius.
Reserved mana can't be used or recovered until whatever is reserving it is disabled, so consider whether you will be able to use your skills with the mana you have remaining. Things that change how skills interact with your mana (like 'Blood Magic') also apply to mana reservation. Heralds also reserve mana and grant benefits that are similar to some of the aura skills, however they only affect you. Heralds also have special behaviours that interact with ailments. Some auras don't reserve mana or don't persist indefinitely. This is true of Vaal versions of auras such as Vaal Grace. Vaal auras have a limited duration but grant very powerful bonuses for the short time they are active.
Each Herald skill interacts in some way with its associated ailment.