Ever-Vigilant Senses Feat 16
Source Pathfinder Impossible Magic
Your eidolon has enhanced senses. They gain a +2 circumstance bonus to Perception and can't be flanked except by creatures that are higher level than them.
They can see Invisible creatures and objects, which appear translucent and are Concealed.
When your eidolon moves within 30 feet of an illusion that can be disbelieved, the GM rolls a secret check to disbelieve it, even if your eidolon didn't spend an action to Interact.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
EvolutionFeats with this trait affect your eidolon instead of you, typically by granting it additional physical capabilities.
SummonerThis indicates abilities from the Summoner class.