Ruby

I love what ruby brings to the table and Sam’s trust in her makes sense
I mean she’s an intelligent demon and the only way at that time to know the knowledge they need to be prepared to fight greater evils than ghouls wedigos demons
Them fighting demons was only a matter of time before they ran into high ranking demons but ruby is a messenger almost to the greater story of hell
She’s kinda the Cas of demonology and I love it

I love how intricate the writers wrote most the characters every character matters to the broader story