You were in the path of a rampaging magical beast. Rather than attack you, however, it resonated with you, and you developed a special relationship. You ground it in the material plane, and it lends you its power in combat.
Barrier Effect: Contractors with the eidolon contract summon their eidolons into their barriers. At 1st level, you gain an eidolon (see below). Whenever you form your barrier, your eidolon instantly appears beside you, so long as it was last dismissed with positive hit points.
Contract Powers: The following are the granted powers of the eidolon contract.
Eidolon (Ex): At 1st level, you gain an eidolon, which increases in power as you level up. This functions as the summoner ability by the same name, treating your contractor level as your summoner level, except that your eidolon cannot use magic gear, cannot have the biped base form, and doesn't weaken as it moves away from you so long as it remains within your barrier. If it exits your barrier for any reason, it vanishes, to reappear only the next time you project your barrier. You may dismiss your eidolon separately from your barrier, but dismissing your barrier dismisses your eidolon as well.
Your eidolon always reappears with the hit points it had the last time it appeared, unless it was slain, in which case it can't reappear in your barrier until the next day, when it returns with half its hit points. You cannot summon your eidolon normally outside your barrier as a summoner could. While dismissed, your eidolon normally can't sense or interact with the Material Plane. However, while performing your remuneration, you can talk to it and it can respond.
Rejuvenate Eidolon (Su): At 4th level, add rejuvenate eidolon (lesser) to your list of spells known as a 1st-level spell. At 10th level, add rejuvenate eidolon to your list of spells known as a 3rd-level spell. At 16th level, add rejuvenate eidolon (greater) to your list of spells known as a 4th-level spell.
Shield Ally (Ex): At 8th level, whenever you are within your eidolon's reach, you receive a +2 shield bonus to your Armor Class and a +2 circumstance bonus on your saving throws. This bonus does not apply if your eidolon is grappled, helpless, paralyzed, stunned, or unconscious.
Standard Tactics (Ex): You and your eidolon are in perfect sync. At 12th level, your eidolon automatically succeeds on any Reflex save it could make against your beam attacks, reducing the damage it would take to 0 with its evasion ability. Your eidolon only benefits from this ability when it is capable of attempting Reflex saves.
Greater Shield Ally (Su): Beginning at 16th level, you double bonuses received from the shield ally ability.
Eidolon Anchor (Su): At 20th level, your eidolon is constantly anchored to your position. Even when your barrier is inactive, its energy and presence manifest from your space. If it has any constant abilities such as auras, they emanate from you. As a full-round action while your barrier isn't projected, you can allow your eidolon to make attacks and use abilities as though it were in your location and shared your space. In any round in which you choose to do this, you benefit from the shield ally ability until the start of your next turn, as though your eidolon were adjacent to you. Your eidolon still manifests normally within your barrier.