Where to hire Black Dragons?

[Amamake]

Originally Posted by PHJF

I just finished up the Necromancer's Castle and lost one of my 3 black dragons in the battle, the three from the Black Tower.

Green Dragons are hired from Thousand Isles, Bone Dragons are hired from Land of Death various locations... where are Red and Black dragons hired from?

You can find the black dragon egg in the Pocket Castle and then clone it via Sacrifice.

EDIT: I think I bought dragons somewhere, but I'm not sure.