Marios participated along with more than 1 million young people from 55 different countries in the 2012 International Letter-Writing competition for young people, which asked young people around the world to write a letter to an athlete or a sports personality they admire to tell them what the Olympic Games mean to them. Marios’ letter to world tennis star Roger Federer, puts the top-seeded tennist in ancient Olympia alongside ancient olympians Diagoras of Rhodes and Polidamas of Skotoussa and conjures up a chat with him.

The jury praised the student’s simple and creative writing style, adding that "modern and historic Olympic values come out very strongly" from the letter and granted him first place.