Genjutsu: Sylph

Genjutsu: Sylph is a Ninjutsu and Genjutsu technique that uses Wind Release to trap opponents in an empty Genjutsu.

Description
When using this technique Akari will siphon wind chakra into the air and direct it around her opponent. Once there the wind chakra will absorb all oxygen out of the air around the opponent to suffocate them for a long enough period of time to where the lack of oxygen damages the cerebral nervous system in the same way as yin energy does for normal genjutsu to trap them in an empty genjutsu. An empty genjutsu is where the target's cerebral nervous system is damaged, but the damage isn't actually creating any effects so their senses remain unaltered and the target remains in the real world. Despite the fact that no illusions or other Genjutsu effects are created the genjutsu still sets off any and all methods of seeing through genjutsu to the fact that their user is in a genjutsu. This allows Akari to force her opponent to not trust their Genjutsu perception abilities regardless of what they are. Akari can use this lack of trust to trap opponents who would normally be immune to Genjutsu because like a Sharingan user because they won't act on what their abilities are telling them out of lack of trust.

This isn't all Genjutsu: Sylph has to offer. Since it is the lack of oxygen that is damaging the opponent's cerebral nervous system and not yin energy the only way to get out of the illusion is to breath in oxygen once again. This makes the genjutsu much more difficult to deal. Not even the Three Great Dōjutsu can help unless they have some way of dealing with wind or cancelling Ninjutsu.

The only drawback is how much time it takes to trap an opponent in the genjutsu. It isn't instantaneous, but takes a few seconds. During the few seconds it is impossible for opponents to pick up on what is going on because of the "ghost" property in her chakra. However, if they are paying attention to what is happening they can pick up on the early signs of suffocation to learn what is happening, to allow themselves to deal with the technique. In addition, any method of cancelling Ninjutsu is very effective against the technique.