RaiwelJace

Design details:

The flowers in Niamh's hair are jasmine, a symbol of love and purity (which she no longer has)

A cut ear, injured before her wedding, during an attempt to suppress her neighbors and usurp power

Partially cut hair, cut herself as a form of shame for her defeat

The patterns on Alvur's collar are astronomical symbols (he's a scientist), but also a symbol of their union

The star around his collar — Alvur is like the "sun" for his people

The colors of clothes, light and slightly "petrol" for Niamh and dark for Alvur, given that she is the princess of the winter (night) fairies, and he is the prince of the summer (light) fairies, the colors should look wrong for their roles

The stylized stars around them, as these are memories in Tommy's childhood perception

So, during the story, prince of the summer fairy and the princess of the winter ones married each other to prevent rising of the conflict between two of their nations, which was caused by the reduction of the magical territories.

Wanting to make their united lands better, Alvur began developing a ritual that would imbue their land, the Hills, with magic. Niamh gain his trust by helping through the researches, but secretly all she wanted was to crash their aliance and the summer faes in general, so she messed up symbols and calculations, that was the disaster recipe.

And Fionnan? Well, he was a changeling one of Niamh followers have as her own son even before the Alvur and Niamh dynasty marriage. When the follower died, Niamh decided to keep the boy as her son. She was never attached to him tho, and Alvur was just curious about his human nature and did some research on his soul (because faes don't have one).

All of this stuff is like the first 25% of the story. I plan to write a story in two parts: about Tommy, human is fairy world, and about Dream, fairy in the world of humans.

So, basically, Alvur in this au is kinda distanced scholar, and is kinda mad scientist trope, Niamh is the deceiver, who wants to continue the cycle of cruelty between their nations, and Fionnan is just a wrong person in the wrong time, who's trying to find his place in the world that was not meant for him.