Elf no Eiyuu Majo Leanne ~Eiyuu Yue no Hokori to Yudan~ RJ01533496

Brisson is a small, isolated island surrounded by several continents, and is inhabited only by elves. The island is rich in various energies, and there are many materials that can only be obtained on this island. The elves have lived for a long time, mainly trading these materials.
However, one day, the neighboring country of Negogund decided that it was unfair for only the elves to have a monopoly on high-quality materials, and raised an army to try to take control of Brisson Island. Everyone thought that Negogund, a powerful nation, would win, but a being called the Witch of Brisson broke the deadlock and Negogund suffered repeated defeats.
Leanne, the witch of Brisson, is called a hero by the elves and a monster by the humans. As long as she is there, Brisson Island will not be unjustly occupied.
Everyone thinks so, seeing Brisson’s unbroken victory for 200 years…