A branch form of Ignition weapons are compression Weapons. In Ignition mode, certain Compression weapons like the Green April are capable of becoming far more powerful when decompressed. Ignition weapons are supposedly quite rare on the lower Floors of the Tower, as Androssi was very surprised when she first saw Narumada. An incredibly famous and powerful group of Ignition weapons are the 13 Month Series, which are only given to selected Princesses.