The guy who murdered most of Morpheus' crew from the Matrix

Anything cyclical. If your freestyling, you rap in a cypher (one after the other). Interrupting another man will break that cypher (unless he's next in line and the dude behind him is falling off). The same concept applies to burning; there is a set order to who hits next (pass it to the left my friends). Never break the damn cipher

To freestyle but not in battle terms

Believed to be one of the greatest hacker alive, we don't know whether he exists. He is believed to work with Anonymous, but also is said that he does Mercenary work. His best hacker friend is 'Blackout' - Most famous for DDoS Attacks on major servers deemed to be invulnerable to traffic-spikes related tango-downs. Blackout is believed to have one of the largest Botnets (or Slaves). Cypher is known for his breaking into multiple computers for no reason and deleting files, he's believed to leave behind a text file (.txt) on the victims desktop with the word Cypher as the filename and Anonymous's motto written on the file itself. Cypher's believed specialty is Cryptography, thus the name 'Cypher'.His knowledge is used for Decryption, and he is said to use his extended knowledge in Cryptography to crack (break) his way into very secured Databases and for dehashing passwords hashed in most secure algorithms. He's very dangeorous, but as any Hacker-On-Steroids, he is vulnerable to dogs and specially curtains.

The process of tapping into your subconcious. A state of mind where thoughts and actoins flow from your mind rather than being instrumented.
Clearly shown in freestyle/beatbox circles and breakdancing.

the number 0, a circle or hole

the sword Strider Hiryu uses to own people

A UAV (unmanned aerial vehicle) developed by Sikorsky. It basically consists of a donut-shaped engine (with rotary blades) with a little camera attached a few feet above it. The Cypher project has really been a black project and will probably continue to be for a while, but its tests have gone quite well. The Cypher can be remote-controlled, or even automated. The images captured by Cypher's camera are relayed to a computer that is managed by a distant specialist, and perhaps various options can be accessed from that laptop, such as NV or IR vision.

Although there are many other UAV drones that have already been deployed into the legitimate battlefield, the Cypher should still be an excellent tool for reconaissance.