Monochrome Factor/YMMV

Alas, Poor Villain: Nanaya's not exactly the most sympathetic guy on the planet at first. Then he gets the crap beaten out of him by Shirogane (who cuts his arm clean off without even batting an eyelash), narrowly manages to escape death by fleeing back to the shadow world, only to promptly have his skull crushed by Homurabi when he arrives. And the kicker is, that's not even the worst thing that happens to him in this manga. Nanaya's life just plain sucks.
Complete Monster: Homurabi. Kaili Sorano might have shown some signs of averting that in the flashback chapter, but chances are any potential sympathy you could have ever had for him will be crushed by Chapter 56.
- When his true motivations are revealed, some fans considered him even more of this.
Crowning Moment of Funny: A number of the pre-opening-theme "recaps" of the previous episode, all of which were heavily exaggerated and only tangentially related to what actually happened. One of them even involved a space battle.
- During Kou's introduction in the anime, he flirts with an adorably befuddled Haruka, only to be stopped short by the boy's elderly butler. Kou then proceeds to hit on the butler--as a joke. The butler, much to Kou's horror, reciprocates. The butler was joking too.
- Shirogane's "math lesson" during the first Naze Naze Neeze. Granted, uh, that could probably also count as Nightmare Fuel.

"First, you have 23 kokuchi. You take 15 from the 23... and kill them."

- In episode three, when Kengo comes in to purify his sister by using salt, Akira, upon hearing what it does, grabs a handful and throws it on Shirogane. Shirogane's reaction is to whine and say he's not an evil spirit.
Crowning Moment of Heartwarming: Any of the Akira and Kengo bonding moments, but especially one of the many from Chapter 36.

"So what I'm saying is... when you're in pain, you can leave your back to me."

Ensemble Darkhorse: Nanaya's role in the early part of the original manga was fairly brief, but especially after the anime he seems to have grown considerably in popularity. Kairi Sorano herself is particularly fond of him, even casting him in her role for the "Sorano Group Workplace" crack segment. His Darkhorse status may have had something to do with his sudden reappearance much later in the manga, though it's hard to say for sure.
Fetish Fuel: Seriously, tell me that Kou literally sucking the darkness out of Kengo by biting him vampire-style wasn't at least partially pandering to exactly this.
Ho Yay: Has its own page.
Karma Houdini: Arguably, Homurabi.
The Scrappy: Fans of the original manga series especially seem to have a strong dislike for Haruka.
Tear Jerker: Every heart-crushing second of Chapter 56, culminating in Kengo being killed by Homurabi.

"Akira... am I... dying?"

The Woobie: Though Kengo starts out as more or less just the Butt Monkey early on in the series, in recent chapters he's started edging into this territory too.