Sustain

Similar to Concentration, a power can have the duration "sustained". What this does and doesn't mean:

• A sustained spell does not use your concentration slot.
• A sustained spell doesn't use a "sustained" slot; you can sustain as many spells as you want.
• Taking damage, losing consciousness, etc does not end a sustained spell.
• Sustained spells must have an energy cost.
• As long as a spell is sustained, its energy cost cannot be recovered. So if you have a max energy of 5, and your spell costs 2 energy to cast, your effective maximum is 3 as long as the spell is sustained. You still must spend the initial energy to cast it; it simply cannot recover until the spell ends.
• By default, all sustained spells end with a long rest, or if you die.