nebuchadnezzar_ii_(fate)
Also acting under the name Gilgamesh II, he's the King of Babylon in the Babylon Singularity of Fate/Grand Order Arcade.
His body is that of Gilgamesh (fate) and the soul is that of Nebuchadnezzar II. In-game he's simply a costume for the regular Gilgamesh (Caster) (fate), rather than a separate Servant.