The Opening of Manaflow ritual, more commonly known as open mana, is a ritual whereby a person becomes capable of utilizing their potentia to cast magic. This ritual requires fasting for some period of time, and maintaining intense focus for that entire time without sleep.
The ritual in its most basic form requires fasting for 48 hours and maintaining focus for that entire time. This will allow the person to use Internal Magic. This will also render the person less resistant against magic, which has pros and cons. The benefits of lowered magic resistance are improved responsiveness to enhancements and elemental resistances, as well as improved responsiveness to healing magic. The downsides are that external magic from others which is meant to do harm will be that much more effective. If the ritual is ceased at this point, the intermediate and final rituals may be completed later.
The ritual in its more advanced form requires fasting for one week and maintaining focus for that entire time. This will allow the person to use External Magic, but if they do not complete the final ritual, they will never again be able to use internal magic. With the exception of Archmagi, sape mages typically cease the ritual at this point. By completing the intermediate ritual, the person's resistance to magic from others drastically increases beyond that of one who had never undergone any ritual.
The ritual in its most extreme form requires fasting for one month and maintaining focus for that entire time. This will allow the person to perform both internal and external magic simultaneously. This ritual is generally only completed by Dragons, and it is generally considered to be biologically impossible for Sapes to complete. Though, some sapes have completed it.