Oh gosh where to even begin with this thing. It is not bad as far as Super Robot Horror anime go, but this is not Rayearth. It is not even an Isekai like every other version of Rayearth is. This all takes place in the city that the characters grew up in. So, what is Rayearth OVA? Well let us start with what it is not. This is not a faithful adaption of the Rayearth manga in any regard, this is basically a fanfic-y alternate universe that involves some of the characters. The reason that this was made is because Hirano (he also was the directorof the Rayearth TV anime which was slightly more faithful until season 2 when it also goes into its own separate place from the manga), basically, this Hirano director guy, he got asked by Clamp to not spoil the manga, they gave him permission to do what he wanted. So basically this Rayearth OVA is more of an Body Horror and Super Robot horror thriller, it takes a lot of influence from an old 1984 anime Fight Iczer One, which is by the same director. Director Hirano has made jokes in interviews literally saying "If you watch Iczer One, you will see that (my original characters from Rayearth) are from Iczer One" (I paraphrased a bit there, cause I feel like it would be spoilers to tell you which original characters that Hirano San invented in his Rayearth anime-verse.
Anyyyyyway. Lol, so yeah, Hirano san he is pretty open with the fact that his Rayearth season 2, and his Rayearth OVA, are just him having fun putting the Rayearth characters in a reboot of his old Fight Iczer One anime. Long story short... Rayearth really needed a manga accurate reboot, so thank goodness we are getting one. Hopefully that remake is good and doesn't use CGi for the mecha... Pls I pray.
Anyway Rayearth OVA, it has great designs and animation (Thanks to the husband and wife duo who founded Studio Gimik, having also worked on this Rayearth OVA). But this is not really Rayearth this is just Hirano san's fanfiction. But honestly bless this man. Did I mention that Hirano literally animated the old 1982 Macross theme song animation? And he animated many of the best parts of Daicon IV, the first animation ever by Studio Gainax. So yeah Hirano san, you are cool dude, you can do whatever you want with Rayearth. though this wasn't great