The reader, his two brothers, his sister, and Niece, are killed. But their worlds God sends them to Highschool DxD world with the powers of Kamen riders.

The reader with Build, ad well as Sento's intelligence.

His 16 year old Brother Connor with Kiva.

His younger 13 year old brother(he is shorter then he should be) with Ex-Aid.

And Michele with OOO.

The reader catches wind of the engagement of Rias and Riser, and sends a letter to Sirzech that instead of a Rating game between Rias' peerage and Risers, Rias chooses 4 People, and they fight against Risers Peerage. Long story short, the reader and his family Cream Risers Peerage and uses RabbitTank Sparkling and destroy Riser.