I think seen an HnK reference very early on. But it's a nice little thing. It's a nice way to celebrate Nitori becoming a notable character other than just a minor one.
@uncreative: I've added the toradora tag because that is the first thing that comes to my mind when Nitori do "that". Fell free to add the tags you think will fit better for that. @LaC: Nitori is one of the partners from SA. Harem growns larger.
Also added Dead_Rising for the Mannequin and Small Chainsaw wielded by Alice and Patchouli respectively. I imagine there are more parodies in this video if we keep looking. Titanic scene in there, maybe?
EmaEiishi said: Is it just me or did Nitori when all sparkles on Engineer's turret?
When I first saw it I thought it was that, too; plus the following tower of hats reminded me of the tower of hats item from TF2. Just coincidence though. I think?