Thor
He kneeled before the Olympian Council, head bowed low in respect for the grecian gods.
"A new prophecy has been issued. My son is yet again in the center of a world changing calamity. I charge you, Thor Odinson, as a guest on Earth, with his health and safety; just as his heritage as a demigod will charge him with yours." Poseidon boomed, the room crackling with the angry tension of the powerful immortal.
"Yes Lord Poseidon." He murmured.
"Then I shall send you my son to guide you and your team to once again come to the aid of the world." Thor would have helped Perseus Jackson either way, but being charged with the task by the powerful god was something else. The Olympians were not known for their mercy on their mortal children, often sending them to fight and die on their behalf without ever meeting their immortal parents. But here was the entirety of the Olympic Council, agreeing to try and protect the single greatest hero of the age. It would be his honor.
"Thank you Lord Poseidon."