I would say that the ending fits with a character like Johan, just as at some time I thought that the ending of MW also fit with the character of Yuuki.
It was definitely a cryptic and ambiguous ending... But I do feel that it has its grace. It was an end in which the mystery dominated.
I just... Idk, Urasawa does such a good job with some of the characters, coming up with secondary character situations and of course the suspense and tension that dominates so much, but there are other characters that I really don't feel like they were that strong, although well, it is difficult to do everything correctly.
Well, despite everything, I feel that this manga is really worth reading, it is one of the exponents of mystery, thriller and suspense in the world of manga, and at the same time one of its pioneers.