Hashiras manifest the Demon Slayer mark when their physical prowess is at its peak. They must also survive the situation that comes before the awakening. For example, a Hashira's heart starts beating at a very fast rate and the body temperature goes beyond expectation ie 39 degrees Celsius.

So, not all Hashira have manifested the Demon Slayer Mark until now, and those who did have already been mentioned in the list. Let's check out all the Demon Slayer characters that have received the badge:

Yoriichi Tsugikuni was the first character with the Demon Slayer badge. But he never trained hard or pushed himself beyond his limit to earn the badge; he had it in his forehead since birth. Well, no wonder he was said to be the strongest demon slayer ever.

Besides that, Yoriichi was the only one who could bring Muzan to his knees during a battle. It's also worth noting that while no one with the mark can survive 25 years, Yoriichi was able to survive 80 years. He almost killed Kokushibo at an advanced age.