Beautiful commission I got from  OsleepyEvil
Check the original post :https://www.furaffinity.net/view/50032813/
Here Oishi is 25 years old, before the accident happened and became immortal.
He was a normal kitsune with an anthro form, taking some lives and souls here and there, taking justice by himself. A lonely (not alone) swordsman that traveled from town to another to help people, defeating bandits and wild beasts.
In one of his travels, he had the job to protect a powerful druid for a long time, accompanying him wherever he went. During that time, the druid taught him the principles and magic, which Oishi learnt fast. He yearned for more knowledge, so he asked the druid to be his mentor. After he learnt everything he could from him, Oishi went to a Magic school hidden in a vast forest. Magicians back then were persecuted, so it was a dangerous objective. In less than 5 years he became as powerful as all teachers together, so he decided to travel through the whole world to learn more.
While he visited the desert he met his future partner Koro, a ice and water mage. He became Koro's mentor, though Koro himself was almost at his level.
Together they found an ancient scroll about immortality, so they recollected all the ingredients to prepare the spell. However, they didn't realise a part of the spell was erased, and that backfired. The spell offered immortality, in exchange of taking away some of their energy. For Oishi, it took his natural ability to produce magical energy, as well as his physical energy :he'd be in chronic pain and exhausted for the rest of his life.
Not the story of his life he'd imagine when he was only a swordsman.

It wasn't a blessing, it was a curse.