Anvilicious: Sex slaves are bad. You are a sick, sick pervert for liking shows like this. You are a horrible person for liking girls beating each other up. And it gets worst from there. It makes Haze's moral look tame in comparison.
Broken Base: The Final episode slamming the audience with a massive info dump and plot twist after plot twist that just stop making sense after a while. For some the show goes from a typically bad fanservice anime into gloriously incompetent So Bad, It's Good territory. For others it just ends up tasteless and hateful both in its ideas and their presentation.
Moral Event Horizon: The main architects behind the remade Platonic Hearts tournament: Miko, Haruki and Natsume. Seeing as they're behind almost everyone of the horrific events that the tournament brings, most notably the sexual slavery brought onto the losers.
Sure it's hopeful that the lady in red can bleed over 15 liters of blood from her head. To cap it off, the brutality of Aya beating her is undercut by the standard punch sound-effects which just end up goofy.
The ending with Natsume's mother silent scream and black view, also known as the "Shallow Cheap Hentai Angst Ending" in the circles.
If you weren't down with this anime for the first four episodes then the infodumped thirty twist pileup in episode 5 will make it all worthwhile.
Nightmare Fuel: Seeing all of Aya's past opponents brain dead, completely mindless just doing stuff not knowing or caring why. The whole scene is pretty disturbing.
Also Aya killing Ryu and continually punching her dead body.
Shocking Swerve: Episode 5 is the epitome of this since everything that happens in it is never foreshadowed in previous episodes.
They Wasted a Perfectly Good Plot: While the show had some admittedly good ideas, the bad writing, animation, and the fact that it wanted to tell something big in just 5 episodes (the last episode being the big reveal) killed any chance of this OVA being any good. Also, its blatant attempt to have its cake and eat it too made said last episode fall flat on its face.