Similarly to Plague Knight's Arcana, they are fueled by a meter, called Darkness. This gauge refills by collecting Darkness Jars, which can be either found through the stages, or by defeating/damaging enemies and bosses, as doing so will spawn an orb of Darkness which will automatically fly to Specter Knight.
Curios are obtained by collecting the various Red Skulls found in each stage, trade them with Red in the Tower of Fate hub and then complete his mini curio-based trial. Uniquely, Curios can be further upgraded to become more powerful. First the glass vessel with the Curio symbol, found the Tower of Fate library, must be filled with three offerings of 1000 gold (3000 gold total). This will summon Legion, who will enhance the Curios for a cost of 4000 gold each.
|Name||Red Skulls Cost||Unlock Stage||Effect|
|Dread Talon||8||Plains||Unleash a powerful close-range strike.|
|Will Skull||3||Plains||Clutch this skull to regain Will.|
|Throwing Sickle||5||Plains||Launch a boomerang blade.|
|Spider Scythe||5||Stranded Ship||Throw a scythe which climbs over obstacles.|
|Chronos Coin||10||Lost City||Slows down everything around you.|
|Bounding Soul||5||Explodatorium||Free a lost soul that reflects off of surfaces.|
|Shadow Mirror||6||Pridemoor Keep||Cast a reflection and attack from a distance.|
|Barrier Lantern||7||Clockwork Tower||Create a shield which blocks projectiles to charge up.|
|Hover Plume||7||Iron Whale||Float for a short time.|
|Judgment Rush||10||Flying Machine||Grasp this jewel to rush at the nearest enemy and strike.|
|Skeletal Sentry||9||Lich Yard||Summon a skeleton sniper and detonate with [Curio].|
|Caltrops||N/A||Collect all Red Skulls||Scatter spikes in front of unsuspecting foes.|
- The word "Curio" describes a strange and interesting object that evokes curiosity.
- Curios were planned to be able to be leveled up to level 3, but instead they made it only up to level 2.