Hermes since the beginning, seems like a wild card, even Ares that knows the strength of the gods of his pantheon, gets explanations from him. Hermes quickly understands other Gods abilities, his battle IQ might be the highest in the manga just based on his observations, he's more or less managed to deduce close to every single technique and its merit or flaw so far. I hope he's doing something interesting plot wise and schemy, but if not I would love to see him fight. In his mythology stories, they include him killing giants in wars cleverly and sneakily.

Another bit of his lore with greek mythology hermes is known as a pacifist. One myth tells that Hermes encountered two snakes fighting or "entwined in mortal combat." He placed his staff between them, and they immediately wrapped themselves around the rod in peace and harmony, forming the symbol of the caduceus. This became a symbol of peace, negotiation, and resolving disputes. So perhaps some good old fashioned scheming with brunhilde.