Accelerator notes that there is no wind when trying to find a way to get to the top of the golem, a major plot point for the Sisters Arc as it was this that allowed Accelerator to use the plasma ball in that arc. Moreover, Isaac Rosenthal would also later try to use a plasma ball and once again being stopped with the help of a Sister.
Accelerator trying to redirect the energy of the golem after Isaac was exorcised from Hirumi's body is a reference to Touma's showdown with Index and her Dragon's Breath. Similar to Touma managing to have Index's Dragon's Breath redirected to space, Accelerator does the same using his Black Wings.
Accelerator saying that there is "...never a dull moment in this city," is a reference to Toaru Kagaku no Railgun, where both Misaka Mikoto (in episode 1 and episode 24 of the first season) and Touma (in episode 1 of the 2nd season) refer to how there is never a dull moment in the city.
This section requires expansion Loss of control, stabbing, standing
The black wings are not fully shown in the manga, with only a small manifestation on Accelerator's back when he is lying on the floor after his battery runs out.
In the manga, Esther leaves Accelerator's room with Huotou outside the window, who despite Esther asking to make their departure quiet, leaves loudly and manages to crack the wall and floor of Accelerator's room. In the anime, Esther removes Huotou from Hitokawa Hasami's body at the morgue before seeing Accelerator.