Meisters are generally individuals with exceptional wavelengths who are paired up with Weapons should both the Meister and Weapon have a compatible wavelength. This is based on the personalities of the potential Meister and Weapon. Should they be compatible, the individual would be able to utilize their chosen partner with ease. However, if one's wavelength isn't compatible, dangerous effects from the rejection can result in injury and possibly death in extreme cases.
Meisters in Soul Eater can be a variety of individuals, even those like shinigamis and zombies. However, it seems that Demon Weapons are the only individuals not able to function as Meisters (unless the said characters are wielding family members, which a bond is responsible for enabling. Also, any character is able to hold Excalibur). The reason behind this is unknown.
It seems to be a prerequisite that a Meister be physically fit. In fact, nearly all Meisters revealed appear to be physically fit. The need to be fit is given credence when Nygus noted that it's a shame that Patty is a Weapon after witnessing her take down numerous opponents without a loss in form. This is further evidenced by the fact that many of the Meisters seem to be able to run the 100m dash in under 9 seconds, with Black☆Star coming in at under 6 seconds. The real world world-record for the 100m dash is 9.58 seconds.
Many Meisters have various abilities which span out to many possibilities. However, Meisters have the ability to allows communication on a spiritual level with their Weapon and, most importantly in combat, allows them to receive or give energy. Many Meisters also, over through the course of Soul Eater and in some cases in Soul Eater NOT! develop the Meister-exclusive ability, Soul Perception, which allows those with it to search for wavelengths and identify them. This is mainly used for localizing people and gauging their potential strength and sometimes even interpreting their intentions.
Perhaps the biggest strength of that of a person who's a Meister is the ability to achieve soul resonance with their Demon Weapon partner. Depending on a character's ability, skill, and sometimes even underlying theme, a character may be able to utilize a soul resonance technique. Some techniques may be unique while others are techniques that're common within a certain group such as scythe meisters. Soul Resonance techniques are perhaps the most powerful type of techniques within Soul Eater; many of them are unique and are the reason why the Witches began losing to humans after the creation of the Demon Weapons.
Although not exactly an ability in the true sense of the word, it would seem to be common among Meisters to have their "themes" present during the use of their abilities. An example of this is Sid, who has an undead theme. This theme of his is present in the name of his attacks, the changing of his weapon into a tomb when performing a resonance, and the fact that he is a zombie. Stein, a scientist who loves to dissect, has stitches present on the blade of Witch-Hunt when he performs it with Spirit. Kid, too, has skulls present on his death cannon when he performs a Soul Resonance with his two pistols.
Types of Meisters
Utility Meister (万能職人, Bannō Shokunin): These Meisters specialize in not only resonating with different types of Demon Weapons, but also can even utilize and resonate with more then one Demon Weapon them simultaneously.
Genius Meister (天才職人, Tensai Shokunin): According to Spirit Albarn, Meister who're labelled this are able to easily master any weapon to an extent If they get even vaguely curious about their weapon form. Franken Stein is the only known Genius Meister.
Bond Meister: Among family members due to a resonance phenomenon called a "Bond", it is possible for family members to utilize their family's weapon form. Differentiating from the fact family members share similar Wavelengths, the drawback is that Soul Resonance techniques are not as strong as with indivduals who're are different.
Death Scythe Meister: Death Scythe Meisters are extremely skilled Meisters whom are known to employ the use of a Death Scythe. These Meisters are highly renown from foes alike, many of them known to be extremely dangerous and formidable, with the majority of them (sans Maka Albarn) achieving a Three-Star ranking within the DWMA.
Great Sword Meister (大剣職人, Daiken Shokunin): A Meister skilled in the usage of a Demon Weapon in which can transform into a great sword. Akane☆Hoshi is the only known Great Sword Meister thus far.
Halberd Meister: Halberd Meisters are Meister in which are skilled in the employment of a Halberd. Depending on the Miester, they may also be skilled with the "spear" potion (making them a Spear Meister), the Axe portion (Axe Meister), or even the Scythe portion (Scythe-Meister).
- Weapons seem to be classed in the same system and rank with their meisters.