Disclaimer: I have only seen the first two seasons of this show, so no spoilers for 2wei Herz, please. Thank you.
I initially debated lumping this show together with Fate/Stay Night and Fate/Zero, but ultimately decided against it because Prisma Illya is a very… different show. It flip-flops between an occasionally very lewd yuri slice of life comedy/parody show and a lore- and mechanic-heavy action show that is more reminiscent of the original VN and the prequel LN, and their adaptations. Even during the action-heavy parts of the story, though, the stakes are never as high as in F/SN and F/Z, because the servant mechanics seem to be different in Prisma Illya, and there’s not as much emphasis on the importance of the Grail.
And that’s actually fine by me, because I prefer the way Prisma Illya does its action. I think the direction is better and the animation style more exciting than in both F/SN and F/Z. Sure, Prisma Illya lacks some of the grander-scale events of Fate/Zero and it borrows almost everything from Fate/Stay Night so I can’t compliment it on its characters or world either, not really, but for some reason I’ve enjoyed it more than my rewatch of F/Z and the recent Ufotable adaptation of F/SN. This might be due to the fact that Shirou’s, for whom I harbour a special kind of hatred, role in Prisma Illya is very minor. But I digress, because I’ll leave the complaints about Shirou for the post about F/SN.
So, I really like Prisma Illya’s twist on the Fate universe, and I really like the way the anime is directed and animated. Which is why it’s kind of unfortunate that the show has so much borderline nudity and sexualisation of elementary school students. I usually don’t bother with those kinds of shows out of principle, but this one has some really good action baked into it, and as much as I would like it to be possible, it’s not possible to separate the two, not completely. Understandably, this makes formulating a recommendation of the show kind of difficult, and it’s why I can’t blame people for choosing to pass on the show even though it has some really good scenes. Oh well, I guess I can still hope that 3rei, the 4th season, tones down the fanservice-y parts of the show in favour of the action.