Canon-OC pairings in 1x1 which totally disrespect the source material! Namely the canon character's personality and the fact that he's not even interested in romance at all, much less with your Mary Sue.

I wish I could mention which character it is without throwing the guilty roleplayer under the bus (this apparently is the only person on the planet with too little self-respect to realize it's a bad idea), but trust me, this shit is fucking [i]egregious[/i] to any self-respecting fan of the video game series in question. I wanted to laugh, or to cry out in indignation for the artists who crafted the games' story, but instead I had to just sit there and let this vaguely dreadful ennui flush over me with my hands at my cheeks, jaw gaping wide and tongue struck dumb, simply staring at the screen as if to wonder whether this person [i]really[/i] had the shameless irreverence to post this back-alley Tijuana abortion on the internet for all to see.