[quote=@JohnWolff]
[quote=@The Silver Paladin]
Eh, why not?
As long as I can use King David, I'm good.
[/quote]

Technically, King David's a mythical (or in this case, religious) figure.
[/quote]

King David qualifies as a heroic servant. He was going to be used in Fate/Apocryoha, and will be used in Fate/Grand Order