The Ortho siblings's Nen abilities work in conjunction--the sister conjures a tag that, when placed on someone, will ink her brother's conjured dart board to the target. The tag cannot be removed until the game ends, not even by themselves. The brother can then shoot the fish-like darts made from his aura at the board and cause damage to the target according to where the darts hit the board. There is no way to avoid the dart because it doesn't exist until it touches the target's body. The siblings run a considerable risk playing the game, since if the older brother misses the last shot to end the game, all the damage accumulated on the target until that point will be carried over to themselves.