A Summoner can call upon the essence of the fire primal Ifrit, the earth primal Titan, or the wind primal Garuda to execute Inferno, Earthen Fury, or Aerial Blast respectively. After the primal attacks, the Summoner's spells will be augmented with the primal's power. Ifrit's spells have a long cast time, but are powerful. Titan's spells are instant cast. Garuda's spells are instant cast and can be recasted quickly, but are comparatively weaker. The ability Astral Flow will also change depending on which primal the Summoner is aspected to.
After becoming aspected to all three primals, the Summoner is able to unleash the power of either Bahamut or Phoenix. The demi-primal will linger and attack in tandem with their summoner, with Wyrmwave being executed by Bahamut and Scarlet Flame being executed by Phoenix. The Summoner if able to further draw power from the demi-primal, enkindling Bahamut to use Akh Morn and Deathflare or enkindling Phoenix to use Brand of Purgatory and Rekindle. In general, Bahamut focuses on massive damage while Phoenix provides healing capabilities to the Summoner.
Due to sharing a base class with Scholar, Summoner retains its ability to revive fallen party members. This makes them extremely valuable as they are able to turn the tide of a battle should the healers become incapacitated.