Healing can have many different meanings in magical girl, and on MahouMUSH, ‘Healing’ typically refers to one of two types of magical aid. Both are for roleplay flavor, and do not have commands or combat system mechanics backing them up.
Cleansing is the act of physical healing. This can take the form of a magical spell such as a 'Dispel' or 'Cleansing Light' or some form of Intelligent Device with a medical purpose, or some sort deep innate healing power. These are just a few examples of possible ways to cleanse injuries and maladies. Cleansing can help speed along healing by removing magical poison, sealing gashes and cuts, giving your magical heart a little energy boost to speed along what would normally be a week's worth of healing in twelve hours. Current environment, location and time allowed to apply a cleansing spell can determine how effective it is- trying to cleanse someone under a youma attack may only allow you to quickly seal a gash or cleanse some sort of poison from the body while not allowing for much else- while cleansing someone in a hospital-styled visit in a peaceful environment allows for more elaborate and focused cleansing back to full health. Humans, magical girls, and beings of dark and corrupted natures can all benefit from cleansing. In the end, how healing affects a character is up to the person being healed. Characters with extensive and powerful cleansing abilities should be based around the concept.
Purification is the act of healing one's heart and feelings from corruption. This usually takes the form of some sort of powerful, love and happiness filled burst of energy in an attack, such as Moon Tiara Action or Happiness Big Bang!, but can also be channeled into someone without the use of some sort of attack if it's part of a character's power set. Brainwashing, corruption of the heart and overpowering negative emotions can be healed through the use of purification. Beings of darkness potentially risk letting themselves be ripped apart on a fundamental level as they're made to realize the truth of love and happiness and what it means to be something other than a horrible monster. Corrupted individuals may be forced to face the darkness in their heart and made to realize the horribleness and wrongness of their path and the fate that lay ahead of them should they continue forward on such a path. Corrupted and darkness filled individuals with strong wills, such as Queen Beryl, Kunzite and Desperaia, still take damage from purification attempts while resisting the overall 'healing' from being purified. Non-Corrupted individuals still take damage from attacks with a purifying element to them, but don't receive any benefit or effect from the purification.
Some magical girls are more conducive to one type of healing over the other. For example, a MGLN-themed mage can make an easier case for a 'cleansing' or 'healing' spell cast from their device, than a purification attack that isn't really something in the MGLN theme, while almost all Pretty Cures have access to at least one purification attack or ability- while not very conducive to having cleansing abilities. That's not to say either couldn't be done, just that it usually isn't the case and might require some additional justification in your application. You may want to specify, in the 'Skills' section of your finger profile, what kind of healing your character does if it isn't explicit. While magical healing is possible, there is no such thing as an 'instant' heal such as a 'Cure/Cura/Curaga' type spell or an RPG Healing Potion/Phoenix Down (all of which cleansing specifically isn't.) outside of major and important events.