In Elden Ring Nightreign, players can revive their downed teammates by dealing damage to them while they are in a near-death state.
The downed player can be revived with about 40% HP if the radial wheel above them is depleted through damage from teammates.
If all players are downed in a Nightlord fight, the expedition ends and they are sent back to the Roundtable Hold.
Tips for efficient reviving include using ranged weapons, daggers for quick revives, and high-damage ultimate skills for instant revival in Elden Ring Nightreign.