If one has summoned one's max number of Alter Egos, and summons the Adventuring Fellow next, all Alter Egos get dismissed. One must always make sure that there's a slot for the Fellow before summoning it.
You can only summon one copy of each Alter Ego. You cannot summon an alternate version of an Alter Ego already present (e.g., summoning Zeid II prevents summoning Zeid).
Alter Egos support you in battle with strategies and tactics you've come to expect.
Alter Egos do not act except in battle, which officially starts after engaging and meleeing once. They will stop acting when you disengage.
If you kill a monster and auto-target another that has aggroed, some Alter Egos will cast spells on it, but they will not melee until you melee.
Certain instanced content will allow summoning even after initial aggro, but not after the player or another player in the party takes direct action on the monster.
Alter Egos use a wide variety of weapon skills (some unique), and will attempt weapon skillchains, and corresponding Magic Bursts. In many instances, they gain weapon skills at much lower levels than players would. Just like in regular parties, careful consideration of what weapon skills an Alter Ego can use will result in better performance overall. Try pairing your Alter Egos with other Alter Egos with which they can perform these high impact moves.
Because their skillchains are not well documented, players are advised to do their own research and experimentation.
Casters seem to gain access to spells at the same level as players.
Alter Egos will wake sleeping party members with Cure and any other healing abilities available to them, such as Rise from Ashes.
Some Alter Egos have synergy with other Alter Egos, which produces different beneficial effects, such as Trust: Uka Totlihn with Trust: Mumor (increased waltz potency). If one talks to another when summoned (indicating a relationship), there is a possibility that they may synergize.
Alter Egos do not affect your experience gain.
Alter Egos' levels and attributes vary based upon the summoning player’s level and/or Item Level.
For regular levels, Alter Egos don't automatically level with the player. They must be dismissed and resummoned to match the player's level. Item Level changes are reflected immediately, which can be problematic with gear swapping.
Alter Egos are not affected by zone potions obtained in blue caskets.
Trust Magic does not cause magic aggro.
Trust Magic cannot be cast while silenced.
Alter Egos are dismissed if the player is Charmed.
Alter Egos no longer despawn when spawning Voidwatch NM, making them usable during these battles.
Trust magic is not available in all areas or types of battle content, but may be expanded in the future.
Special: These Alter Egos act very differently compared to players. They may also have a regular job as well.
Monster: These Alter Egos are non-humanoids that use their species' special moves. They may also have a regular job as well.
Passive: These Alter Egos are non-interactive NPCs that give a bonus as an aura. Most are technically Geomancers, but do not have to cast or recast. They cannot be interacted with in any way and will do nothing else but play follow the leader.
Some Alter Egos have Auto Refresh, but no other indication of what other job they possess.
Some Alter Egos have forced attribute bonuses that may make them more or less useful for certain situations. For example, Selh'teus appears to have a capped hit-rate regardless of content level, and Trust: Lilisette II has a very high crit-rate (75% on Apex Crabs) independent of content level.
Note: Each and every alter ego does not have the full complement of abilities that a player would have, only a limited sub-set. This means job traits, job abilities, weapon skills, spells, songs, ninjutsu, you name it. Each one also does not have all of the same abilities of the original character on which it is modeled. Each does have the same weapons and armor, but, once again, only limited versions (e.g., Trust: Lhu Mhakaracca's axe, Guttler, to which she speaks).
Usage in Parties
Players can summon Alter Egos while in a party containing other players.
Only the party leader is able to summon forth Alter Egos.
Alliancescannot be formed when in a party comprised of both players and Alter Egos.
The following are rewarded over the course of the Rhapsodies of Vana'diel Missions. All come in the form of ciphers to be traded at the appropriate NPC (must have completed the quest offered by the NPC to whom you trade the cipher).
After joining a Unity Concord, and the moment you obtain a Partial Personal Evaluation of at least 5 points, you gain access to your Unity leader. You lose access to your Unity leader if, at the weekly Sunday conquest points tally, your weekly Unity Personal Evaluation drops below 5. Your PPE resets to zero, and you regain access the moment your Partial Personal Evaluation reaches 5 again. You do not have to wait for the next weekly tally.
To see Unity info, from the right-hand menu, choose Status > Unity.
Completing Unity (RoE) objectives gains evaluation points quickest, while defeating enemies that are not Too Weak also works (at a lesser rate).