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.
Creepy Child (Depending on who you ask, the anime might extend to this, too)
Nightmare Fuel (The Persoenlichkeit's strongest attack involves her familiars pinning down its target. Alfimi gets up close and personal, unsheathes the Lichkeit's katana and stabs the living shit out of it. Skewering motions make the sight of the attack painful, until you realize Time Stands Still during the attack, meaning the target isn't even feeling anything until afterwards)
OT3 (You think Kyosuke will just settle for Excellen and not both her and a loli clone? Fanworks say you're wrong)
Try OT4...of sorts: before her return in Original Generation Gaiden, there existed a LOT of fanart featuring the "Nanbu family" and their very, very cute twin daughters. See Dead Guy Junior for more
You'd expect: For Gai to stay close to the Nadesico, as Aestivalis units guzzle energy and the battleship in question can quickly recharge it.
Instead: Being Gai, he charges headlong towards the Jovian Lizards and burns all his energy just getting there, therefore becoming unable to move and thus requiring Akito Tenkawa, in his own Aestivalis, and eventually the Gandor team to bail him out.