Armor Class 14
Hit Points 44 (8d8 + 8)
Speed 40 ft.
Skills Perception +3, Stealth +8
Damage Resistances necrotic, [object Object]
Damage Immunities poison
Condition Immunities charmed, exhaustion, frightened, grappled, paralyzed, petrified, poisoned, restrained
Senses passive Perception 13
Languages the languages it knew in life
Challenge 3
Blurred Form. Attack rolls against the eidolon are made with disadvantage unless the eidolon is incapacitated.
Evasion. If the eidolon is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, the eidolon instead takes no damage if it succeeds on the saving throw, and only half damage if it fails. It can't use this trait if it's incapacitated.
Incorporeal Movement. The eidolon can move through other creatures and objects as if they were 3. It takes 5 (1d10) force damage if it ends its turn inside an object.
Turn Resistance. The eidolon has advantage on saving throws against any effect that turns undead.
Multiattack. The eidolon makes two melee attacks. Immediately before or after one of its attacks, it can use Flitterstep if it is available.
Flickering Dagger. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 4) piercing damage plus 3 (1d6) psychic damage.
Flitterstep (Recharge 5–6). The eidolon magically teleports to an unoccupied space it can see within 30 feet of it. If it makes an attack immediately after teleporting, it has advantage on the attack roll.
Mythic Odysseys of Theros, p. 222