Compression Licenser are "giant", "huge", "massive" individuals, creatures, artificial beings, or living beings that are known to be able to "resize" their body size. It's not their born ability, but an additional ability which resulted after they made contract with a Guardian.
A Guardian has the rights or authority to "organism compression". So, the people or creatures who are too "big" can control their body size. It unknown whether you can directly resize your body after you made contract with Guardians, or perhaps the "resize process" should be carried and done by floor officials first.
Compression Licenser usually has a body size and features resembles to that what you would or might call as a "giant" beings, with a very tall body height and massive body weight. Their "giant size" makes them inconvenient to move around and doing activities in the Tower. So in order to make their movements convenient, their body size will be reduced drastically. They will become smaller in size after being "compressed".
Advantages and Disadvantages
There are big advantages but little disadvantages of becoming a Compression Licenser.
- You can become smaller and bigger at will. You can use it as a strategy in fight and combat situation.
- Add an element of surprise against enemies. The enemies will not see what's coming.
- There are many cases where Rak Wraithraiser, one of many compression licenser, was seen to not use his compression license and transform into his big size body in fight situation. Whether this has something to do with compression licenser disadvantages or his own will not to transform, were left unexplained.
Known Compression Licenser
- Rak Wraithraiser: In Rak's case, his body was "resized" and "compressed" by Yu Han Sung, a floor official, High Ranker, Test Director and Test Admin of the Second Floor.
- Vespa: She was seen to transform into huge size, capable of carrying and transport many people. It's pretty contrast to notice, remembering that she's actually pretty small in a fight situation.
- "God" of guardians: Unlike other compression licenser, "God" of guardians can compressed his own body without receiving compression license from any Test Director or Test Admin. Rather than given, it's more likely one of his special ability. 
- Yukan: He appeared compressed after his defeat by the hands of Jyu Viole Grace.
- Evankhell: It's still unconfirmed if Evankhell is a compression licenser, but according to SIU, she has a normal height at least 7 metres.
Notes and Trivia