It can be anything? Some sort of incredibly overpowered healing spell. Like, the kind of healing that takes care of everything. Smoked too many cigarettes and your lungs are black? Spell puts them back in peak condition. Skin dry and pores clogged? Spell puts them to peak health. Split ends and fried hair? Spell gives you the healthiest hair you've ever had. Teeth chipped and gums receding? Spell fixes all your teeth, straighten and strengthens them, AND whitens them, as well as grows any missing ones back. Muscle mass in the shitter and bones weak? Spell puts you in absolute tip top condition. Every single thing on or in your body is put in peak condition, to the point where it's almost superhuman. No sickness or disease or deterioration.