Magical Onslaught
Feat 10
Source Pathfinder Impossible Magic
Your eidolon's attack provides you an opening for one of your spells. Your eidolon makes a melee Strike against a creature, and then you cast a 1- or 2-action cantrip targeting the same creature. If your eidolon's Strike hits, the creature is Off-Guard against your spell (if it requires a spell attack roll) or takes a –2 circumstance penalty to its save against your spell (if it requires a saving throw). If your eidolon's Strike and the spell deal the same type of damage, combine the damage of both for the purpose of resistances and weaknesses. Both your eidolon's attack and any spell attack roll you make count toward your multiple attack penalty, but the penalty doesn't increase until after both attacks have been made.
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.
SummonerThis indicates abilities from the Summoner class.
TandemActions with this trait involve you and your eidolon acting in concert. You can't use a tandem action if either you or your eidolon can't act, if you haven't Manifested your Eidolon, or if you've Manifested your Eidolon in a way where it isn't a separate entity (such as with the Meld into Eidolon feat). Tandem actions often let both you and your eidolon take separate actions, but these must be actions taken separately by you and your eidolon; you can't use a tandem action to take another tandem action.