Changes In Classes - a tl;dr

Nobles / Lords (Entirely Homebrew Class)
This class most closely resembles the 5e Paladin and Fighter class, but is different enough to constitute it as an entirely home-brewed class. [No magic or religion, they use crests, and they have battle flags.]

Mages (Wizard and Sorcerer Combined w/ Homebrew)
Mages take from the 5e Wizard class but replaces their arcane traditions with school majors. Additionally, similar to wild sorcerers, they gain chaos magic and wild chaos surges.

Witches (Homebrew Warlock Class)
Witches take from the 5e Warlock class but replaces their otherworldly patron with the 5e sorcerer's font of magic, being gained at level 1, and the metamagic feature, being gained at level 2. Like the sorceress, the warlock may convert their sorcery points, now dubbed chaos points, into spell slots.

Upon level 6, Witches attain an additional spell slot.

Crest Priest / Priestess (Only Available Subclass Priest)
As there are no deities in the universe of the Grancrest, there is only one subclass that follows the 5e Cleric class. This subclass replaces all archetypes that a 5e archetype would have. Additionally, Crest Priests or Priestesses replaces their "turn undead" feature with "render chaos." At 5th level, this turns into "consume chaos."

Crest Artists (5e Fighter w/ Chaos Magic)
Crest Artists may choose from any 5e Fighter Classes excluding the Arcane Archer & Eldritch Knight archetypes. In addition to being crest artists, they may use the crest arts in their tables. This is a powerful buff to the regular 5e fighter class.

5e Fighter Classes Excluding Arcane Archer & Eldritch Knight / Spell-less Revised Ranger (Allen state changes below)
The 5e fighter class does not use any chaos in any way. Instead, they focus on their training, and may be called more powerful then the usual 5e fighter. They gain an extra feat and has a 1d12 hit die instead. They also have advantage on all charisma rolls when speaking to commoners or village elders.

The spell-less revised ranger takes from. . . and replaces their. ..

Hunters Mark to your wisdom modifier and replaces one of your two maneuvers. 1d10 hit die reduced from 1d12 (Fighters get a free feat, you do too still)

5e Rogue Classes Excluding Arcane Trickster
The 5e rogue class may pick from any archetype and may replace their first expertise with "Shadow Knives Training." At level 3, they gain "shadow step" and at 9th level they gain "shadow dimension." If the player does not choose to take shadow step or shadow dimension, they may replace it with another expertise in a skill.