I am the Storm that is approaching

Hey my name is Y/N L/N, and I'm just or rather was an average man, that really liked the Fate Franchise especially the Grand Order group(And all the characters that origin from there[that appeared for the first time]). So I went to a Convention as a male version of Goddess Rhongomyniad everything was fine until I bought a really cool looking copy of Rhongomyniad from a Mercurius cosplayed man.
Next thing I knew was that I am in a city called Maretropolis(Whoever did that name deserves death), along with the fun fact that I am a sort of composite version of ALL the Artorias, with the spirit of Goddess Rhongomyniad inside my head or Spear or Mind. Not so fun fact I'm also stuck with a F******ing fairy