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.
Crack Pairing: This fic absolutely REVELS in them! Let's see... Cirno x Hustler One, Lana Nielson x Sakuya Izayoi x Hong Meiling (As in, all three of them in a relationship with each other at the same time.), Shu Shirakawa x Yukari Yakumo, and Omega Chronicles!Omega Zero x Female!Alucard (Both of whom are probably the parents of Remilia and Flandre Scarlet, don't ask how.)
Ho Yay: It's not hard to see Daiyousei as having some romantic feelings for Cirno. There's also the fact that Hong Meiling has an obvious attraction to Sakuya, who has an obvious attraction to both her and Remilia Scarlet. Said attraction is shared with Lana (who is essentially Sakuya's mirror image in terms of personality). Given how MagnumPhoenix refered to this fic as "The Yuripocalypse", there will probably be more to come.