Nope I think it's a trail by the people who are gonna give him the sword so like it's his conscious and that's why the sowrds dissaperd after the mysterious person showed up
They have not died, the twins are illusions made by shadows / sand (can't remember which), essentially, to test Jin in the desert as a part of his trials. His master is the same, although she is an accumulation of Jin's personal memories, that's as far as it reaches
Is it reall omgosh??? Are the twins real d3ad? Is that really his master??