You have awakened a trace, a fragment, of magical power; your biological makeup has changed to withstand the nature of magic. All magus who practice the thaumaturgical nature of biomancy possess an organic flesh sack inside their bodies that helps with the gathering of the vestiges of the lifeblood of the universe. Those who practice possess a more evolved body as a result of the mutations that they gain from casting spells or the backlash from spells that have forever scarred their body.
You start with a beginner-level understanding of the main branches of biomancy; however, through experimentation and research, you can branch outside the current understanding of biomancy.
Shaping: When most people picture those who work with flesh, you are the first thing their mind goes to. This is the school of manipulating the flesh of beings who are still alive and even those who are dead in order to change the bodies of the living into something else, using magic to influence the evolution and creation of flesh into something that it was not before. You are able to cast magic and change the biology of others and yourself, augmenting the already existing biology. Others are often able to tell those who practice this type of magic based on how they look, as those who delve into shaping often leave differently than how they came in, grafting additional arms, eyes, or even growing tentacles in order to attack offensively. Most people do not wish to get into a fight with Shapers, as they will turn them into biomass that they will then use to further augment themselves.
Monster Manipulation: This is the school of magic relating to the creation of new life and a subsection of Shaping. Those who practice this magic are fond of creating monsters instead of augmenting themselves, distancing themselves from combat, not wanting to dirty themselves with the blood of their enemies, and creating elaborate monsters to do the job for them, such as bears that can breathe fire, dragons that can turn invincible, snakes with the upper body of a man that can poison their enemies, and so much more. The more imaginative the one who created the monster, the more features that could be hidden in the monster that they created. They are not bound by the biological laws of the universe, being able to fit more into their creations the more they have spent researching this branch of magic, even creating all new forms of beings that have abilities beyond what normal biology should allow.
Blight Craft: The first plague that was ever discovered was the result of a biomancer who did not properly seal the container that they kept their research in. This field of study is that of transmuting flesh into diseases and plagues, able to create plagues that even the most deadly of creatures could fall into. Creating parasites and diseases comes as second nature; you are able to create diseases that shouldn't exist with enough research and study, corrupting others into misshapen blobs of flesh, turning their eyes into bees, creating boils, and so much more.
As you progress into biomancy, you can start to crate biological monsters with magic alone instead of relying on already existing biomass, creating abominations that evolve the more magic that you put into them. At mastery, you could even start to shape the world around you as you reach beyond the limits of mortal biology.