Mastema's origins are unknown, but it was previously owned by the governor of the town of Joyou. Later, it came under Run's possession after he seduced her as a part of his plan of getting into the military and changing the Empire from within. After Run was reanimated as Kurome's corpse puppet, the wings turned from white to black.
After being freed from Yatsufusa's influence, Wave came to possess the Teigu and dual-wielded both Mastema and Grand Chariot for the first time.
Mastema allows its user to gain wings which give them the ability to fly for a limited amount of time; Run was shown to be able to fly at high speeds and displayed high maneuverability, as well as the ability to hover. It also enables the user to shoot feathers or launch one of the wings toward enemies, both easily capable of piercing through flesh. However, Mastema is only effective when attacking at a long distance and is at a disadvantage in close range, as shown when Run was fighting Akame.
God's Wings (神の羽根, Kami no Hane): The trump card of Mastema, which gives the wings the ability to reflect an opponent's attacks. When used, the disks split into segments and the wings turn into what appear to be an ethereal substance, which allows them to be shaped into a protective shield. This trump card can also counteract Mastema's weakness at close range. In the anime, this ability instead allowed Run to break a large stone pillar hurled at him into pieces.
- Mastema is the name of a fallen angel or a demon in Jewish mythology. His character is a personification of the Hebrew word, "mastemah" (משטמה), which can mean "hatred", "hostility", "enmity" or "persecution", and was portrayed as a warrior angel of destruction leading his own army, or as an agent of God that punished evil. This could be a reference to Run's character, as he was a merciless killer despite his angelic appearance and fought against evil both on the Empire's behalf and with his own motivations.
- Despite being translated as "Thousand-Mile Flight", a ri (里) is actually an old Japanese unit of distance, equaling approximately 3.927 km or 2.44 miles.
- The trump card, God's Wings, is depicted as a yellowish white in the manga and blue in the anime.
- The governor of Joyou was shown with only one of the disks in use; something never seen with Run.
- The wings' disks can connect together to form one disk for easy carry and concealment
|Members:||Run · Wave · Kurome|
|Deceased:||Bols · Run · Seryu Ubiquitous · Dr. Stylish|
|Teigu:||Demon's Extract · Grand Chariot · Mastema · Yatsufusa|
|Lost Teigu:||Hekatonkheires · Perfector · Rubicante|
|Puppets:||Apeman · Desta-Ghoul · Doya · Henter · Kaiser Frog · Natala · Rokugoh · Run · Wall|