Also if we refine the system a bit, what can or can't be shared needs to be more limited so there aren't obvious loopholes; like how do we treat outer items (death note), foreign implants (kiroshi eyes), makeable self-items (zanpakuto), biological implants (mystic eyes of depth presumption), soulbound cursed items (aztec gold coin in pirates of the caribbean), types (chakra, reiatsu, yoki), sources (dantian)