These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Base Breaker: The anime adaptation, especially with how certain characters get treated and/or get derailed in the character development department. By far the biggest complaint was how the anime had severe cases of Mood Whiplash, swapping between serious drama and slapstick comedy every five minutes. The ending was also not well-received by fans.
Complete Monster: Riku Ousei, all the way. The other Katou minions, and Hisataka himself, have varied grades of redeeming qualities. Ousei is capable of coldly killing civilians with a Kill Sat just to make a point, and taunts Kouichi about that.
Case in point, Hisakata Katou looks like a pimp who talks like Lelouch, Sawatari goes about the place in a blue trenchcoat/suit thing with flames on the sleeves and pant legs, Demitri wouldn't look out of place in the aristocracy, and Masaki is dressed up like a goddamn cowboy!
Nightmare Fuel: The one time you see one of Izuna's nerve crack visions, involves the person affected seeing Linebarrel grow many times bigger than its usual size and transfrom into a massive deamon.
Viewer Gender Confusion: 'sup, Satoru! His being male did nothing to stop the Anime adaptation from sticking him in a bikini during the Beach Episode. Also they refer to him as a she in the dub