Oboro tells the students of Shoka Sonjuku the truth about Utsuro and his ultimate goal.
And when the wielder dies, 
the key disappears with them.
.وعندما يموت حامله، يختفي المفتاح معه
Cuando uno de ellos fallece,
la llave desaparece.
E quando o detentor 
morre, o lacre some.