They did a Nanoha Vivid on Z/X Code Reunion by making Azumi from the first season and made her the main protagonist!.
The weirdest thing about Z/X Code Reunion is where this season is placed, like Azumi doesn't really say much about the events of Ignition AT ALL, it's almost like she had her mindwiped (almost like retconning Ignition in the process) and have her get re-introduced into the Z/X's all over again. But right from the off Azumi and Rigel gets on a mission to attend some all girls Z/X's school to "save the world" where she befriends 4 other girls where
they have to be a team in fighting the enemy Z/X's, the 5 however are in the worst class (Rank E) and having a literal demon instructor, their teamwork grows as they get through their trials and tribulations.
At the start, the anime does get into some coincidental situations especially with the formation of the main core cast's team, but latter on the formula becomes a character-centric plot on each of the team members whilst Azumi and Rigel's relationship ALSO grows in between it and mind you some of the member's backstory or development as stock generic as their personalities are, their backstory are uhhh something else even for a card game based anime.
Matoi Shinonome voiced by Maria Naganawa is your typical shy girl but at the mist of Z/X Invasion her power kinda went out of control unable to save her older sister thus she soon grows attached to Ena looking her up as an older sister. Yuni comes from a rich family and doesn't want to go through Ira's rigorous training and at one point tries to run away, from this Shuri Kijino gets her episode alongside Yuni as she was scammed into being thought to be samurai. So the core cast of Rank E Team is ehhh in terms of characters and their development slim, maybe except Matoi, the rest gets their solo episodes and that's it developing really little with all of them achieving "Overboost" to help in thier battles and hope they don't get kicked out of the school in the first place. The core crux and focus is towards Azumi and Rigel and their retconned redevelopment of their relationship. Now Ena is the only one missing and she along with Azumi probably gets any sense of character arc, Ena especially in the finale.
Minor characters for the most part are rivals due to the core cast being in the lowest ranked team. The student council team as well as Rank A Team gets a episode to themselves and Ira due to being rank E's team, she gets her running gag of being a great teacher but an absolute demon instructor and trainer and as much as she's a literal demon instructor she still cares for her Rank E Team. Minor character wise, it's slim much like the majority of the core cast.
The animation done by Passione was ehhh ok, they did a few shortcutting here and there from reusing shots, eg. transformation sequences and attacks even, Passione did have a decent character design with LA finding out the entire character cast have this "geass"-like irises by default, but the character designs are on the typical moe side, expected from a collectible card mobile game adaptation (yes this was adapted through that). The battles were ehhh ok, few beam blasts here and there and the battle animation was ehhh ok, but still in line to the moe side of things through and through even when the anime got more serious as rare as it was.
The voice cast was expectedly moe typical from the character designs, with the only core cast from ignition coming back being obviously Yui Ogura and Aya Uchida as Azumi and Rigel respectively. Maria Naganawa as Matoi was actually pretty decent doing her usual loli stoic cadence whilst Ania Suzuki did a foreigner not really schtick as Shuri and Miyu Tomita doing a psuedo-gyaru rich girl cadence as Yuni. Inori Minase as Ena and Yui Ogura as Azumi was probably LA's top picks of the anime by default though by default.
Z/X Code Reunion's flaws are simple in some ways, one is again the placement of this season in relation to Z/X Ignition and the retcon of Azumi (seriously can ANYONE tell LA where this season is placed). Due to this retcon we had to re-introduce Azumi and redevelop her even though she was somewhat developed already in Ignition. Next is that the new core cast have slim to nil development as characters and are stock bland, but this flaw can have a bit of defence that LA will agree with, that of this is a "teamwork" synerized anime as the group helps each other through their developments episodes or arcs, from Yuni with Shuri to Matoi to Ena and Ena with Azumi so LA can give this flaw a slight bit of leniency and finally the animation is ehhh ok done by Passione not so much a flaw but has tendency to derp at times.
Z/X Code Reunion is your typical moe anime about "friendship always prevails" scthick with some yuribait thrown in and retconning the first season in order to make Azumi the main protagonist and yeah to be honest, Azumi being the main protagonist was interesting but with all the retconning going on detracts it a little, sure she's the typical sick girl needing to stand her ground that she can get hurt in the mist of battle with Rigel ALWAYS being by her side being a good thing and a bad thing, but it doesn't help that she along with Ena is probably the only pillar to Z/X Code Reunion to stand on, where the slim core cast development, flimsy world building and again the retconning makes this season of Z/X a bit hard to get heavily invested in and in one part, it doesn't need to be cos it's a yuri moe anime with space battles, but on the other hand standing on one pillar makes thing hard to balance things out a try to really like it. Not that Z/X Code reunion was boring or horrible or anything, just those flaws REALLY outweigh the positives that it did have.
Z/X Code Reunion isn't disappointing, nor horrible...how LA saw...it's just....meh.