If I understand this correctly, a hypostasis is essentially a separate instantiation of a property or attribute that God has? Thus, the Logos is an instantiation of God's Intellect, the Holy Spirit an instantiation of his Love, the Father himself an instantiation of his Sovereignty or Unity or something of that sort. The hypostases may even instantiate properties of God in unique ways so that the Father is God's Wisdom as he who is Wise, the Son is instantiates Wisdom as the Wisdom of God, and the Holy Spirit instantiates Wisdom in its own unique respect so that, in each sense, all of them are Wisdom, but distinct instantiations of it. Hypostases are in some sense singular, but they're not concrete in the same respect as how instantiations of universals in the material cosmos are concrete, existing, substances, in their own rights i.e. particulars. Since the Hypostases are entirely immaterial, simple, and transcendent, and subsistent within one another and exist in an eternal act of mutual indwelling through communal and relational love or harmony (perichoresis). There, are, then, three subsistences within God but one substance, and the subsistences of the Godhead represent the personal identity of God as different identities that Yahweh has and reveals himself as to creation. It is true, however, that one of the Hypostases (the Logos or the Son) does instantiate itself, or rather within itself, a concrete nature which subsists in it (Jesus's human nature). Jesus's personal identity is identical with the second Hypostasis of the Godhead while the human nature subsists as a perfect copy, image, or instantiation of the second hypostasis of the Godhead.
