
Quick answer — Stereo Dive Foundation performed 3 anime themes, including "PEACEKEEPER" from That Time I Got Reincarnated as a Slime Season 3, "STORYSEEKER" from That Time I Got Reincarnated as a Slime Season 2, "AXIS" from Nobunaga the Fool.
Stereo Dive Foundation performed the anime theme songs "PEACEKEEPER" (That Time I Got Reincarnated as a Slime Season 3), "STORYSEEKER" (That Time I Got Reincarnated as a Slime Season 2), "AXIS" (Nobunaga the Fool).
Stereo Dive Foundation's first listed anime theme is "PEACEKEEPER", the opening of That Time I Got Reincarnated as a Slime Season 3.