Crona

Crona is Ragnarok's meister, and was initially under Medusa's orders (and control) to take any soul they find, be it evil or good. Crona is a very naive and submissive person who is constantly pestered by Ragnarok in the form of noogies and threats to eat their share of food. Crona does not like to fight but Medusa normally introduces a spell into their mind that increases their aggression. Crona's blood has been entirely replaced with "black blood" which both protects them from physical harm and provides a degree of healing. Ragnarok, originally a normal weapon, was melted into the black blood before the transfusion, which causes their siamese nature. Crona is taking trial courses at Shibusen so they learn the proper way of a meister. Crona is trying to adapt to interacting with more people which may take some time because of Medusa's abusive treatment of them. Often, Crona stays in a corner of any room they are in and will cower in said corner if they are feeling nervous. Crona doesn't know how to interact with others, but is slowly learning how to, thanks to Maka. Maka can easily tune in to Crona's soul wavelength to understand and calm them when needed.