Most summoners forge a bond with a single, powerful eidolon, but some summoners seek to control a variety of creatures. The master summoner sacrifices the power of his eidolon in favor of summoning a plethora of otherworldly creatures to aid him.
A master summoner’s class level is halved (minimum 1) for the purposes of determining his eidolon’s abilities, Hit Dice, evolution pool, and so on. The eidolon otherwise functions as normal.
This ability replaces the summoner’s normal eidolon ability.
Starting at 1st level, a master summoner can cast summon monster I as a spell-like ability a number of times per day equal to 5 + his Charisma modifier. The summoner can use this ability when his eidolon is summoned. Only one summon monster spell may be in effect while the eidolon is summoned. If the summoner’s eidolon is not summoned, the number of creatures that can be summoned with this ability is only limited by its uses per day. This ability otherwise functions as the summoner’s normal summon monster I ability. Other than these restrictions, there is no limit to how many summon monster or gate spells the summoner can have active at one time.
At 2nd level, a master summoner gains Augment Summoning as a bonus feat. He does not have to meet any requirements for this feat.
This ability replaces bond senses.
The broodmaster and master summoner archetypes can potentially have 5, 10, or even more summoned creatures in play. This is a deliberate feature of these archetypes, and means that the summoner can potentially be a strong candidate for “solo” adventuring by one player. However, in the hands of an inexperienced or moderately experienced player, dealing with all of those creatures in combat can take a long time, forcing other players to wait extended periods between their turns in the initiative. It is strongly recommended that GMs only allow these archetypes for experienced players, or decide on a way to speed up the summoner’s turn (such as by allowing other players to control some of the summoned monsters).
Pathfinder Roleplaying Game: PRG:UM