Scathe.
FFVII Summon Materia have no story at all. Even don't have some log to tell their story.Espers have little to no backstory. The first summon you get has some story, but the rest are just there. You get them through the storyline. Half of them are optional with no story. They appear, you fight them. The end. The only "story" you get is from the game's beast log which tells some info on them that you don't get in the game otherwise.