The reader gets into an Accident, but isnt dead, a transdimenional being pulls him into  a pocket Dimension and tells him that he would've died. She offers him a chance to be a hero in another world, but with the choice of power he gets, he asks for the Miraculous box with all the Miraculous and Kwami, along with the Grimoire. He explains he'll prioritize the Moth Miraculous, that way he can get the feel of the power he gives to temporary allies, and learns who's best to trust with power and those who are not. He'll utilize the other Kwami and Miraculous if he ever needs it.

He'll first use the Peacock and make a Senti-monster, a Ladybug(the hero), and have her fight while he gets the hang of maintaining his power and control. When he can maintain the transformation after a few uses of the Miraculous' special ability, he'll give the Senti-monster its Yamuk, so it can live how it wants.

Yes, I'm actually a fan of this series, im a fan of shows like Monster High and Ever After High, so this likely wouldn't be much of a shock.