YMMV / Citadel of the Heart

• Aluminum Christmas Trees:
  • The androids that exist in Sword Art Online: Special Edition, Reflection Code, and Digimon Re: Adventure are essentially higher grade, mass produced versions of androids such as Actroids that already exist in real-life, minus the much more advanced AI and more human-like capabilities.
  • Ruki's soda addiction being akin to a G-Rated Drug complete with mentions of withdrawal and all that entails with what would normally follow someone who is The Alcoholic, but considering Ruki is only 17 at the start of the fic, actual alcohol was off-limits, so soda was used in it's place. While normally the usage of such a thing was very mundane and trivial in the eyes of the author, who simply depicted this as due to having experienced withdrawal-esque reaction to a lack of soda and his overall addiction to Mountain Dew, apparently some of the author's friends didn't realized that experiencing an addiction or especially a withdrawal from soda was even possible, leading to the author having to explain it from past experience on his own behalf, and thus leading this example to becoming this trope.
• Nightmare Fuel: In the beginning Chapter 5 of the Reflection Code story when William is looking around Lyoko, a specter suddenly appears before him whispering in an echoey voice before vanishing is pretty eerie.