Chaoz Airflow is a famous 1.9 demon level by Sumsar.
The level is well known for its fast sequences that inspired many creators in their levels (e.g The Robotic Rush...). Chaoz Airflow used to be considered a very hard demon in early 1.9, but after the realization of far harder levels (e.g. Cataclysm, Bloodbath, Sonic Wave), it has been revalued as medium demon, easy for veterans. Its difficulty goes near Golden Haze, an other level of that period.
The level starts with a very easy cube with simple jumps. Next, there is a short auto part which transitions to the first moderately difficult part of the level, a tight ship corridor with gravity portals and double speed. After that, a shorter ball part appears, which seems easy, but hides some trolls and annoying spikes. It is followed by a difficult mirrored wave, where the spaces seem large but are quite tight because of the huge amount of invisible 1.6 saws. It spans until the drop, with a gaining speed duwblades. The same thing happens to the following UFO, with also gravity portals. When the player reaches the free part of the UFO, he takes the triple speed and goes to the hardest part of the level, a dual mini ship full of saws and thorned slopes, crucial timing is required. The player, then, goes to an other wave part, but is easier than the previous one. The following UFO is an extremely difficult part of the level, because of crucial timing and tighter spaces. The third wave is in a dual mini mode, then single, but not too extreme. The next part is probably the most famous of the level: a mini dual cube that is symmetrical, but is hard and very confusing because of invisible mini blocks and spikes. After a short easy ball, the level ends with a moderate mini ship with tight spaces. The creator's name is visible when the level is cleared.