The Synthisters (魔骸者 Magaimono, "Magaimono") are a race of synthetic and modified humans in Akiba's Trip: Undead and Undressed. These humans have been treated as subject and had undergone the process of DNA modification as part of human experimentation to create an "artificial vampire". However, these humans alter from the natural Synthisters, an ancient form of modified humans from the olden times and some even belonging to the clan known as Nighteater.
They are often called a "Monster", or other names such as "man-made vampire". They are also referred to as the human figure, which are smeared with desire. The modified humans gain tremendous physical abilities such as reflexes and endurance, as well as immortality. With a difference to normal human beings, having a big weakness to the sun which can cause them to purify, although some have a high tolerance to the sun which may not affect them or need to expose more skin for it to take effect on them.
Their appetite can consist of draining energy from humans but a majority live of a normal appetite, consuming food normal for a human and get by their daily life. Although, there are times where if they focus on a human diet, then they may have abnormal portions.