Belladonna's magic revolved around the body. Her body mostly, as her class made it incredibly difficult to project her mana outwards. It was why, for example, she chose to carve the runes onto her flesh instead of using her armour for it.
If it was on her armour, while they could be more versatile and replaceable, it would be more difficult for her to use consistently and would require more energy to bridge the gap between skin and armour.
However, that did not mean her energy was restricted entirely to her body. She could, with struggle, push it outwards. A technique that could be improved with physical contact, hence how she could Infuse Beans' meat and which was also the basis for her [Shredding Strike] skill.
Compressed and focused energy, forced out of the body with physical contact as the medium.
