Troubadour

The Troubadour is a third-party Pathfinder class that's built around blending together the Spheres of Power and Might. As such, they're considered a Half-Caster, but get 2/3 BAB and Practitioner progression right off the bat.

The insane combination of the Vigilante and Bard, they're built around having multiple Personas. Multiple in this case means they get more than two personas, which sounds like the book-keeping nightmare that it sounds like. Each of these covers a specific archetype which can differ in multiple ways including alignment (so long as it's within one step), name, appearance and even race (but not their size and abilities). This sounds familiar considering it's an expanded version of the Vigilante's Dual Identity; and you can even combine the two features and talents. To differentiate the Personas, they gain Tropes to give them unique purposes for the Troubadour to exploit; and they can also take Actor Trainings for their standard mechanics of disguising. They can even gain some Bard-like features; like Masterpieces and Versatile Performance! The similarities to Vigilante continue; especially as each Trope gains a particular feature, such as the Hero getting full BAB (much like an Avenger), Cunning Servant getting Inspiration, Lovers becoming lite Bards, Mentors becoming a full casters, Monsters getting natural attacks, Scoundrels getting sneak attacks, and Villains being a bizarre fear-based subclass.

5E

Of course, the massively simplified playstyle of 5E meant that the logistical nightmare known as the Troubadour needed a much-overdue overhaul. To this end, the Troubadour was renamed the Alter-Ego, made into a native initiator (with certain ways to pick up casting) and the number of personas chopped down to two. Both the ordinary identity and the secondary persona can select tropes which lets them imitate certain classes, such as the Dragon gaining the Barbarian's Rage, the Hero stealing Fighter features, the Lover granting Bardic Inspiration, and the Mentor giving half-casting (and with the proper persona, this can turn into FULL casting).

The Alter Ego is perhaps the most involved form of a subclass out there, as they not only provide alternate features, but they also come with unique ways to transform and adopt new personas if need be.

• The Chemist goes full Mr. Hyde by requiring the Alter Ego to drink a potion to transform, granting all sorts of radical transformations one would see on an Alchemist.
• The Empowered channels the power of magical girls, complete with a transformation sequence. This also provides access to casting, which can be stacked with the Mentor trope for even better casting.
• The Possessed has the Alter Ego have a second person haunt their body, allowing them to swap out identities very quickly, but these uses are limited due to the toll such a process takes. This does help out, as eventually this leads to the two identities having their own separate pools of health as they level up.
• The Troubadour gives the closest to the original PF class with all those other identities, but each identity will only have access to one trope and nothing more.
• The Vigilante truly flaunts the Batman origins of the Vigilante, as it allows for some Bruce Wayne tier shenanigans involving who is around when things happen.

The Third Party Classes of Pathfinder
Psionics:	Psion - Psychic Warrior - Soulknife - Wilder Aegis - Cryptic - Dread - Marksman - Tactician - Vitalist
Path of War:	Stalker - Warder - Warlord - Harbinger - Mystic - Zealot
Akashic Mysteries:	Daevic - Eclipse - Guru - Nexus - Radiant - Rajah - Stormbound - Vizier - Zodiac
Spheres of Power:	Armorist - Elementalist - Eliciter - Fey Adept - Hedgewitch - Incanter Mageknight - Shifter - Soul Weaver - Symbiat - Thaumaturge - Wraith
Spheres of Might:	Armiger - Blacksmith - Commander - Conscript Savant - Scholar - Sentinel - Striker - Technician
Spheres of Guile:	Agent - Courser - Envoy - Mastermind - Professional
Champions of the Spheres:	Prodigy - Sage - Troubadour - Dragoon - Mountebank - Necros - Reaper Warden - Crimson Dancer
Pact Magic:	Pactmaker (formerly known as Medium)