B y the demented standards of fantasy anime, this is fairly straight; the weirdest thing on show here is probably a unicorn-wolf who scoffs pink frosted doughnuts. And in case you’re having trouble distinguishing the interchangeable faerie folk who populate the cast, this second theatrical outing for the series has (unusually for feature-length anime) a handy explainer at the start: namely that the protagonist is a murdered salaryman reborn as Rimuru (voiced by Miho Okasaki), an amoeba-like blob who rises to become demon lord of the realm of Tempest. In fact, Rimuru features minimally in this sequel. He and his retinue are invited by the Celestial Emperor to holiday at a luxury island resort; the only thing spoiling their sightseeing, fishing and carousing are the laser-like bursts of “nuclear magic” periodically blasting over their heads. But they are told they are in no danger: the target is the nearby undersea kingdom of Kaien.…