Fire and Water, Closer than we think

From the moment I set my eyes on him, I knew our journeys were entwined together, and this boy was not going to be normal. They were much more similar than thought. They both knew they weren't ordinary from a very young age, they had a well-crafted mask and deflect with humor to count a few.
Basically, this is Percy and Leo who knew each other from the past fanfic.