Adapted from classical RPG, most of the story serve everything that you expect from epic fantasy medieval story. Here is some example :
Each character had specific skill and racial that determine their job/classes (human-knight/thief/priest/magician, elves-shaman, dwarf-warrior, etc)
Saving the princess from evil sorceress
Defeat dragon that lurking in cave on the journey
Defeat ‘Legendary’ dragon with special weapon
Battle between ‘Light’ and ‘Darkness’
World building started from battle between two gods that represent chaos and order so the conflict continued from there in next generation
Evil wizard/Sorceress is mastermind of the conflict between two faction
I may oversimplify these elements but the execution is somewhat enjoyable despite lot of cheesy exposition. Every character had slightly personal motivation other than saving the world from the ‘eeeevvviiillll’ kingdom. Even the antagonist had same drive as protagonist which make them interesting instead presented as one dimension villain.
This OVA had 13 episode which contains 5 part story which make the story more plot driven with very fast pacing. It is unfortunate because I like the interaction and development between each character despite how short it is. But you can get detailed explanation from the light novel and manga.
I personally like the story even the OVA present outdated and repetitive animation plus cheesy and corny dialogue. The story and character act oftentimes subvert my expectation with decent reason which make this story enjoyable to anyone who like this kind of fantasy story.