Another light novel might be 'Grimgar of Fantasy and Ash'. In this story, there are elements that touch on the idea of a necromancer - like system. The world has magic and abilities that could be related to necromancy, such as dealing with the dead and using their power in a way that fits within the context of the overall system of the story.
One popular system necromancer light novel is 'Overlord'. In this novel, the main character has necromancer - like abilities within a game - turned - reality system. It's full of interesting world - building and character development.
Typically, they involve a system, like a game - like or magic - based system that governs the necromancer's abilities. For example, in some novels, the necromancer has to level up their skills of raising the dead within the system.
Finding light novels directly related to the 'Metropolisation System' is a bit tricky. But consider light novels like 'Log Horizon'. It's set in a virtual world where the cities are important elements. The governance, economy, and social structures within those cities can be seen as a form of system. Although it doesn't explicitly mention 'Metropolisation System', the concepts of how the urban areas function and develop are quite prominent. Also, some cyberpunk - themed light novels often deal with complex systems within large cities which could be relevant.
One popular necromancer light novel is 'Overlord'. In this story, the main character has necromancer - like abilities and controls a vast army of undead. Another great one is 'Death March to the Parallel World Rhapsody' where the protagonist also dabbles in necromancy - related magic. And 'The Rising of the Shield Hero' has elements of necromancy as well, with the main character being able to summon undead creatures to fight for him.
Another one might be 'Grimgar of Fantasy and Ash'. While not solely focused on a necromancer girl, it has elements of necromancy in its magic system. The world - building and character development in this light novel are quite engaging, making it a great read for those interested in the genre.
Power and its consequences. Necromancers often gain great power by controlling the undead, but this comes with a price. They are usually shunned by society, so there's a theme of isolation.
One light novel that might be related is 'Sword Art Online'. It has a complex system within the virtual world which could potentially have some elements related to the Neromancer system tags. Another could be 'Log Horizon' which also features an in - game system that might share similarities.
One popular 'over powered necromancer light novel' is 'Overlord'. In it, the main character has necromancy - like abilities and is extremely powerful. His control over the undead gives him an edge in battles and in ruling his domain.
There are many light novels out there and without more information about this 'catastrophic necromancer light novel', it's hard to give a definite recommendation. However, you could also check out some light novel review websites. These sites often have user reviews and ratings that can help you find something similar if not the exact one.
One could be 'Overlord'. It has elements of dark magic and powerful, otherworldly beings which share some similarities with what a necromancer might bring. Another is 'Re:Zero − Starting Life in Another World' which has its share of dark and magical elements that might be somewhat comparable.