I'll get to this soon, but I'll tell you one thing: I got all of my characters' names (excluding River) from google translate using the words Bell, Squishy and Soil. Try to find out their languages.

Sprites' costumes:
River: Run, Jump and Dash done
Timbre (Yet to be introduced): Idle done
Puni (Yet to be introduced): Nothing done
Ithir (Yet to be introduced): Nothing done