The sun's grace( 7DS x Highschool DxD x Testament of the new sister devil)

Siegfried is a young man of 17 years of age, he quite talkative and often considered an innocent soul, he doesn't like sketchy people and/or perverts...lets just say they don't last too long when he's around. He seems pretty normal for his age. But what people don't know is that he's a Child born of Goddess clan blood, more specifically the son of Mael of the four archangels or otherwise known as the 'angel of death'. He is also a descendant of the owner of the holy sword Balmung, Siegfried the dragon-blooded knight. What happens when he, his Triplet Siblings and his Father travel to Kuoh, what events will transpire, what will happen when a certain red-haired devil takes interest in the young man...well let's find out

I do not own Highschool DxD or Nanatsu no taizai or Shinmai Maou no Keiyakusha, they're owned by there respective authors