Once Upon a Demi-god

I don't own any of these characters except the ones you don't know from Rick Riordan or Once Upon a time. And for clarification:

Rick Riordan's character:
Percy Jackson
Annabeth Chase
Grover Underwood
Clarisse
Trevor
Conor
Piper
Jason
Hazel
Frank
Leo

Once Upon a Time Characters:
Emma
Mary Margrot/ Snow White
David Prince Charming
Hook
Regina
Mr. Gold (don't want to spell his actual name every time so well go with Rumble or Gold)
Robin Hood
Zelena

My characters:
Maxine
Elena
Amethyst
Isaac
Amanda

Characters that are used but don't belong to anyone:
Hercules
Meg
All the gods of Olympus