Out of the six, Flint is the oldest, as evidenced by his examine in addition to various dialogue interactions with him. It is revealed that he is very inventive, and as such had invented the Pitch can to start instant fires.
^Lina, "The Firemaker's Curse", RuneScape. "It's a silly story. Flint raised me, so I was always interested in fire. The first fire I made was when I was 10; I took one of his inventions that made sparks. I used it outside the house, and it threw a spark on to a poor chicken! The chicken was fine. Just a bit singed."
^Flint, "The Firemaker's Curse", RuneScape. "I care for her as my daughter. I found her when she was a tiny baby, all alone on the plains. Saradomin knows how she had survived. I raised her as my own child. I couldn't bear it if anything were to happen to her."
^Flint, "The Firemaker's Curse", RuneScape. "Ah, well, I'm not sure there's much I can tell you about myself. I'm getting boring in my old age."
^Flint, "The Firemaker's Curse", RuneScape. "Player, if you're going to be making fires, you should take this. It's something I invented for places lacking in wood. It's a pitch can. You can light the pitch directly to create a fire in front of you, or where you stand. You don't need logs, but the fires are much hotter than usual, so you won't be able to jump over them like wood fires."