A long time ago i spent a week of nights playing Warcraft III's singleplayer on its hardest difficulty. At the time i had no single nickname, but typically used one associated to Vasili Zaitsev. After winning, i used Archimonde as my nickname, after the biggest baddy in W3. Over time clan mates, and even friends at school began to call me "Archi" for short. It stuck. I shortened it to Archi, and later began using days of the week behind it, typically Monday, Tuesday, and Wednesday.