Masteria Expansions, Names and the proof for each

Well the way I see it is that Steel-fist Jack landed on the shores of Masteria (through a accident like his crew's boat sunk or he was knocked overboard) and made his way to CWK. He was the only pirate at CWK and thus had no real guilds under him, but he was powerful enough to get a spot as a Grandmaster and to leave a mark in the history of Cwk but not enough for the versalians to copy.

Jack is just there for a while, he doesn't really qualify as a grandmaster (Everywhere it talks about grandmasters, there are always 4.) but I think they remember him because of the novelty. He's the only person who fights like this, they find it really interesting, and then when he leaves, they start incorporating parts of it into their own disciplines (Which is why we see guns and Knuckle-claws about).

The timer gets reset once you enter the doors :3

Doesn't really matter if the whole rest of your party cleaned out the room.