Shadow Spirit

A base spirit that can be summoned by the Main Character for 10 morale & stamina if they chose Shadow Affinity at the start, summoned Shadow Spirits will come with the ShadowAffinity trait. If you selected UniqueStarter for added difficulty at the start, you won't be able to summon them and the one you are given will not have ShadowAffinity. Alternatively they can be captured in shadow mini-biomes.

They can also be summoned by Hildy for 10 morale & stamina, whose Shadow Spirits will come with an additional Regenerating trait. While it's a good trait in general for enhancing survivability, shadow units often rely more on Mana to tank in their ShadowForm so you might be more interested in them for purposes of fusing to other units.

Base spirits are generally weak and will be priority targets for most of their training cycles. It's advised to keep them safe in combat encounters.

Like all base spirits, Shadow Spirits can be reshaped upon hitting their level cap, increasing their Max Level and some genes but going back to level 1.

Like most shadow units, Shadow Spirits and their following evolutions tend to be stronger in shadow and vulnerable outside of shadow, but they mostly come with shadow spreading mechanics.

Shadow Spirits can be evolved into a Shadow Bringer or a Shormy, which evolves further into a Void Bringer, a Hole Worm, or a Shadow Djinn; a Death Fly which evolves into a Shadow Fairy; or a Shadow Nymph or a Celestial which don't evolve further.