HP paro, written out of a sudden idea in 15 years, Durmstrang-Marco × Hogwarts-Ace;
The plot is slow and has many private settings, which is almost a semi-fantasy of HP's world view;
The deputy CP is probably Kilo.
The starting time of the text is set to 1849 (it will be changed if bugs appear in the future), please don't do too much research~