Greatest? O_O, Show me the way U_U
Fūinjutsu is the art of sealing things. The fundamentals are sealing and releasing, but it is more complicated than that. In order to seal something you need, an object which is the thing you are going to seal. A vessel, which is the thing that is going to contain the sealed thing. Sometimes a trigger, this could be anything preset into the vessel that forces it to activate. Binding, which is the seal itself, which is what will contain the object. Chakra, like alot of things it needs chakra to maintain/activate the seal. But because it's chakra seals are not permanent and they happen to get weaker over time. A key which isn't essential, but you may and one if you wish. This is a method to unlock or break the seal, pre established when the seal was formed. Almost anything can be a key.
( Isshi Tōjin ) - Light String Formation
This is a short range barrier that stops people from leaving the area. Since it's short range, that's not alot of space. It can't be used on people stronger than the user and combining two of them makes it one rank stronger. Which will increase your chance of preventing them from escaping.
( Fuuinjutsu: Kōmu Kekkaijutsu ) - Sealing Arts: Crimson Mist Barrier Jutsu
This allows the user to summon a thick wall of mist, as it is short to long range this can be done almost anywhere on the battlefield. This technique masks your sounds, allowing you to move covertly whilst your opponents vision is obscured. Your rank determines how far you can actually use this jutsu, so you need to take note of that before you use it at just any range. Just like the range the length of time it can stay on the battlefield for is also determined by rank.
(Mugen Hōyō) - Infinate Embrace? I think is the one you are talking about, because not only does it hinder the opponent from molding F rank moves. It takes chakra away from them and gives it to you. Which if this happens the jutsu pays for itself, since it costs 20 and absorbs 30. The jutsu is also supposed to be used in conjunction with other restraining techniques as well making it harder for the opponent to get out.
I don't have any questions, I also like (Fusen no Kekkai) Tag Barrier ^_^