Aside from the first fight scene in Golden qualifying as a Rule of Cool moment, the battle itself actually makes perfect sense in the games own mechanics, providing you believe that Persona 4: The Golden Animation is a New Game Plus version of Persona 4: The Animation. As both Myriad Arrows and Maziodyne are skills that target all enemies on the field and the fact that a Slipping Hablerie would have no way to inflict damage against an Izanagi with the Null Physical ability.
Episode 7: It's Cliche, so What?
In the original anime, Narukami battles Adachi rather calmly, only getting riled up to gave a Shut Up, Hannibal! speech before he defeats him. Here though, Yu shows a breakdown as the fight goes on. Why? Because unlike the first adaptation, Yu considered Adachi a friend and important part to him. Thus, Yu is reacting like he would if anyone he befriended did that.
Episode Eight: "Not So Holy Christmas Eve"
Episode Eight starts with the second opening from Persona 4: The Animation as opposed to the new opening for Golden. While this may seem like a strange choice at first, it makes perfect sense when you realise that the whole party has lost their memories of Marie, thus making the world now appear no different to how it was in the original series.
So this is supposed to be a New Game Plus, right? Well, then where was Marie in the original Animation? Yu must have never bonded enough with Marie to regain his memories of her in the first anime. She was always there. The Team has just forgotten about her, similar to how they forget for two episodes of Golden. They just never saved her in the original Animation.
Doubles as Fridge Brilliance as this also explains the odd structure of Persona 4: The Golden Animation and why each episode is referred to as memories. The scenes from Golden are in fact the missing memories of Marie from the original Persona 4: The Animation and the New Game Plus elements are their to simulate Yu recalling how the events actually transpired. The entire point of Golden was simply to fill in the gaps between events the original series, with the repeated scenes replacing the original episodes where Marie was absent.
