Seihai-kun (Grail-kun) is a parody character from Carnival Phantasm and basically the mascot version of the Holy Grail. He started as part of Type-Moon's TMitter April Fools' Day joke, but became memorable enough to stick around in the actual show.
His whole thing is playing this Doraemon-style magical helper—characters come to him with problems, he hands them a "solution," and it's always just a kitchen knife. The tools have ridiculous names like the "Friendmaker" or "Servant Strengthening Device," but the joke is that he's implying they should solve their issues violently. His advice basically amounts to "stab your way out of it," dressed up in absurdly cheerful gift-box packaging.
The best bit comes in Episode 11, where he gets weirdly meta. He sits down with Lancer and literally walks him through every death the guy's suffered in previous episodes, warning him that as the show's designated comic relief, any of these could actually stick. It's almost like he's genuinely trying to help. But here's the thing—Lancer manages to dodge every single death Seihai-kun predicted. He just dies in a completely different, unforeseen way instead, in a new route he somehow creates with the Holy Grail. And Seihai-kun just sits there in the background being smug about it, making cryptic comments.
Content compiled by AnimeList.moe from publicly available sources.
