I'll be adding a few more things to this list, especially in the non-human sections, but this is what I have planned out at the moment (minus a few things that I thought were too spoilery).

Basic

Earth

Fire

Light

Water

Wind

Variant

Cloud

Lightning

Shade

Sound

Stone

Arcane

Chaos - This is currently considered an arcane type, but it might be subject to reclassification once it's better understood.

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Crystal

Life

Mental

Null - Technically, this means no affinity, but it's considered an arcane type for classification purposes.

Void

Combination

Combinations have a synergistic effect. Magic users with combination type affinities can use each of their component magic types (though not as well as a pure affinity can), as well as using magic unique to their combination.

Blizzard (Crystal + Water + Wind)

Blood (Life + Water)

Clay (Earth + Water)

Firestorm (Fire + Wind)

Flare (Fire + Light)

Ice (Crystal + Water)

Lava (Earth + Fire)

Metal (Crystal + Earth)

Mirage (Light + Water)

Sandstorm (Earth + Wind)

Snowcloud (Cloud + Crystal)

Storm (Water + Wind)

Swamp (Earth + Water + Life)

Thunderstorm (Lightning + Water + Wind)

Wood (Crystal + Earth + Life)

Rainstorm - Nickname for storm affinities with a strong water primary.

Windstorm - Nickname for storm affinities with a strong wind primary.

Spectral Beast Magic Types

Replication (Mimics)

Puppetry (Revenants)

Mythic Beast Domains

Dream (Ki'shiu)

Forest (Ket'yia)

Forest Sanctuary (Ket'shiu)

Island Sanctuary (Naslunal)

Snow (Essu)

(We'll find out what the "sanctuary" part means later. You'll have to just speculate about it for now. 😉 )