Ticket

Tickets are worn by a ghost after the person died. A new ghost has 1 ticket.

A white ticket leads to heaven or rebirth while a black one leads to hell. If a ghost collects 100 black tickets, he can exchange it for a white ticket. If the ghost lose all his tickets (stolen or taken by other ghosts/reapers) then the ghost turns into the Dead.

The tickets give the ghost power. A reaper's power is said to be graded as at least 100 tickets.