Regina and Robin Hood may be on 'solid ground' but is there a bumpy road ahead? What's ahead for Regina (Lana Parrilla) and Robin Hood's (Sean Maguire) complicated relationship on ABC's Once Upon a Time? How Does Hades Differ From Past 'Once Upon a Time' Villains? As Regina and Robin proceed through the Underworld, their relationship will stay strong despite some complications coming up along the way.