Usage: Illumi uses needles for various purposes. They are infused with his aura and he can manipulate anything they pin at his own will.
History: This is Illumi's way of disguising himself as someone else for as long as he wants. He can apparently manipulate his face on his own will without needles but can only maintain it for a limited amount of time.
Usage: Illumi can pin his or anyone's head with his needles to manipulate and change the face structure. He can also make other people's faces deform and if the needles aren't removed quickly, the face will remain deformed for eternity.
History: This ability was used on Killua as child to control him and make him follow Illumi's commands by voicing him phrases in his head.
Usage: Illumi can pin a person's brain and manipulate his thoughts with phrases he desires. The target when confronted with a situation that matches Illumi's phrases will have those words repeated many times in his head to make them follow his commands.
Human Manipulation (Needle Humans)
History: This ability was revealed on Chapter 328.
Usage: Illumi can pin any human he desires with his needles and make them follow his commands until they die. The Needle Humans will be boosted with Illumi's aura though the needles.
Thought Manipulation was what Illumi used on Killua from his early childhood. Illumi had implanted a single needle in his brain to make him follow his commands. This is the reason why he disqualified himself from the final test of the Hunter Exam by killing Bodoro. Killua then returned home and chained himself up in his cell under Illumi's commands through this ability.