Ichibei, what the hell?!

Peaceful life after the most terrifying war in the history of creation was going great for Kurosaki Ichigo. His studies to become a translator were complicated by the reputation that had followed him since high school. So the only place he managed to get hired was Kuoh Academy - thanks to his father's connections - for the position of English teacher.
Now he lives in a peaceful world, and no one will bother the strongest Soul Reaper and his loved ones. Or so he thought.

P.S. The author loves foreshadowing and hints. The reasons behind the story, the plot, and how the world works have all been thought out. So a lot of things won't be explained right away - only much later, through many chapters, either directly or hinted at beforehand - so feel free to leave comments.

As canon for Bleach, the manga up through the Thousand-Year Blood War arc is used (none of the filler arcs happened, and no filler-exclusive characters exist, except for zanpakutō spirit forms). For the TYBW arc, the anime is canon (specifically, the three cours released as of the time of writing).

For DxD, the anime is used as the primary basis.

The plot structure is built on the foundation of the Bleach universe, since its mechanics are much better established.

The mechanics of how the fanfic's world works, and the reasons that made it possible, will be explained within the story itself.

P.S.S There are many characters from whose perspective the story is told. Ichigo isn't the main character in the traditional sense; his main story is over. But he is a participant, as well as in future plot changes, which will lead to the DxD canon, along with the events that unfolded within it, being completely uncontinued at a certain point.
Also, many moments from the DxD light novel translation were rewritten. I don't know how much the final result will differ from the translation you read, but keep that in mind.