Necrosis Magic (壊死魔法, Eshi Mahō) is one of the Black Arts and is a Lost Magic, banned by the magic council after witnessing its horrifying qualities. This magic allows the user to break down good blood cells, essentially breaking down the target's limbs.
Necrosis Magic, not to be confused with Necromancer Magic, this type of Magic focuses on decomposing its targets cells, tissues, and organs. It was originally developed by Mage Doctors to help kill the bad cells and cell tissues in diseases and help with bone surgery. But of course, the magic fell into bad hands and Dark Mages started to use it to kill people's good cells and decompose the cells which in turn breaks apart the tendons, muscles, tissues, and then either breaks the limbs apart or/and kills the person altogether. It wasn't long before such magic traveled to Fiore and the Magic Council caught wind of it, and it was outlawed.
- Rotting Malice (腐敗マリス, Fuhai marisu): A cloud of hazy red instantly starts to decompose living things in the surrounding area. The more magic applied, the deadlier the spell.
- Devil's Decay (悪魔のディケイ, Akuma no dikei): Silver generates a large purplish black sphere and sends six beams of magic to strike the target and slowly rot away at the skin. Any weak lesser being in the surrounding area instantly perishes.
- Virus Beam (ウイルスビーム, Uirusubīmu): Just as the name implies, Silver launches a laser like beam of viruses that can get into the target's body through their ears, nose, mouth, or in some instances, even their pores. The body is then flooded with all kinds of deadly viruses.
- Parasite Swarm (パラサイトスウォーム, Parasaitosuu~ōmu): Silver summons forth a huge swarm of all kinds of parasites to attach themselves to their victims. But unlike other parasites, these find their way into the bloodstream and slowly eat away at the blood cells.
- Contamination Aura (汚染オーラ, Osen ōra): Silver is able to taint the surrounding air with deadly gases that slowly eat away at the skin without the target even knowing it. All they'll garner is an itchy feeling until the notice their skin peeling away.
- Atrophicize (萎縮, Ishuku): A large purplish substance oozes out of Silver's hands and spreads along the ground like a seeking carpet, looking for anything with life and cells to destroy by slowly taking a hold of its victim and degenerating its cells.