I've known this for a while but I'm bringing it up now because I'm really curious about whether or not anyone else knew this.
In Tokyo Ghoul and Tokyo Ghoul : re, Ishida Sui (author) draws the number of tarot cards on characters within the chapter or chapter cover. These numbers go along with corresponding tarot cards and mean different things, so it's kind of like foreshadowing or added sybolism.
Juuzou's hairpin for example - Xlll is the number 13. The 13th tarot card means death. In a certain chapter of Tokyo Ghoul Juuzou's hairpin changes to a different number, but I don't want to spoil anything so...
There are more straightfoward examples, like you can actually see the number 2 on a person's head not just two lines. I would tell you, but once again I promised no spoilers so unless you ask me (or notice for yourself).....
If you look closely, a lot of characters in Tokyo Ghoul: re have numbers on them too.

I was wondering if anyone else saw this or understood it. If you did or even if you didn't I would really like to know.