Highschool dxd x Fate/Grandorder

Clock Tower/Chaldea create a Humonculus from the blood of King Athur(artoria Pendragon), Abraham Van Helsing, the Gremory, Phenex, and Sitri familys. this Humonculus believed he was a regular boy, but wished for family. he learned his origins, as well as his true identity, a prototype for a final product, his blood, along with a descendant of Solomon (Olga Marie Animusphere), were used to give birth to a pair of twins who are enhanced with the elixir of life(philosopher stone), giving them the same lifespan as humans. he breaks into a rage and takes his homunculus daughters. five years later hes revealed to have relocated to Kuoh town.

the mage organization in Fate has a project to revive the heros of the past by using a Familiar seal type bond between Mage and resurrected historical figure. Artoria Pendragon appears alongside Jeanne D'arc and kick Kokobeils ass, and taking excalibur(and removing the holy attribute, cause it originally never had said attribute)

Mash is a Humonculus(designer baby) born from Galahad.
Olga Marie is the descendant of Solomon
Rin is Possessed by Ishtar.