Banished from the sky.

In general, my HC for eye colours are the following:

Fire - red or orange

Water - blue or black

Air - grey or white

Earth - green or brown

Quintessence - gold or purple

Ghouls with more than one element usually have eyes of the colour of one of those elements (the eye colour doesn't necessarily mean that's their stronger element, also, sometimes they can have heterochromia)

Also, unglamoured Ghouls have black sclera, most of them glamour it white, but some don't

Extra:

Special/Phil (Quintessence+Fire Ghoul, gold eyes)

Cowbell (Earth Ghoul, dark brown eyes)

Era 0:

Phoenix (Fire Ghoul, red eyes)

Flood (Water Ghoul, dark blue eyes)

Horizon (Air Ghoul, white eyes)

Rock (Earth Ghoul, light brown eyes)

Era I:

Omega (Quintessence Ghoul, gold eyes)

Alpha (Fire Ghoul, red eyes)

Avalanche (Earth Ghoul, brown eyes)

Chain (Water Ghoul, light blue eyes)

Abyss (Water Ghoul, black eyes with black sclera)

Nimbus (Air Ghoul, grey eyes)

Era II (new Ghouls):

River (Water Ghoul, dark blue eyes)

Era III (new Ghouls):

Pebble (Earth Ghoul, brown eyes)

Delta (Water Ghoul, blue eyes)

Mist (Water Ghoulette, light blue eyes)

Popestar Era (new Ghouls):

Ifrit (Fire Ghoul, orange eyes)

Aether (Quintessence Ghoul, lilac eyes)

Ivy (Earth Ghoul, light green eyes)

Mountain (Earth Ghoul, forest green eyes)

Zephyr (Air Ghoul, white eyes)

Dewdrop (Water Ghoul, light blue eyes)

Dewdrop (post-transition to Fire, iridescent light blue/orange eyes)

Era IV (new Ghouls):

Rain (Water Ghoul, black eyes)

Cirrus (Air Ghoulette, dark grey eyes)

Cumulus (Air+Quintessence Ghoulette, light grey eyes)

Swiss (Earth+Quintessence Ghoul, gold eyes)

Era V (new Ghouls):

Sunshine (Air+Fire Ghoulette, red eyes)

Aurora (Air+Water Ghoulette, blu/indigo eyes)

Phantom (Quintessence Ghoul, purple eyes)

Chamber Ghoulettes:

Astra, voice (Quintessence Ghoulette, dark purple eyes with black sclera)

Calypso, cello (Water Ghoulette, black eyes with black sclera)

Dione, cello (Water Ghoulette, black eyes with black sclera)

Nephele, piano (Air Ghoulette, white eyes with black sclera)

All Ghouls used to be bound to a person in the Clergy (usually the Papa in charge at the time of summoning, but it can be changed), if the person dies, the Ghouls bound to them die as well. It was a way to ensure that they would be loyal to their Papa. This was changed around the time Aether, Dew, Ivy and Mountain were summoned, so they were not bound to anyone. All previous band Ghouls were bound to their respective Papa, so they died at the end of Era III.

Era 0 Ghouls used to be bound to Nihil, but after he stopped being Pope their link was broken. They are still alive but kind of keep to themselves.