Legendary Summoner Feat 20
Source Pathfinder Secrets of Magic
Prerequisites Master Summoner
Your ability to summon extends past your other spellcasting. When you sacrifice a 9th-level spell slot to gain two summoning slots using Master Summoner, you can use those slots to cast summoning spells heightened to 10th level.
You can't use these spell slots for any purpose other than casting the summoning spells, and you don't count as having 10th-level spell slots for other abilities or rules.
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.