Erebos

In Greek mythology, Erebus ( /ˈɛrəbəs/), also Erebos (Ancient Greek: Ἔρεβος, "deep darkness, shadow"), was often conceived as a primordial deity, representing the personification of darkness; for instance, Hesiod's Theogony places him as one of the first five beings to come into existence from Chaos. Erebus features little in Greek mythological tradition and literature, but is said to have fathered several other deities by Nyx; depending on the source of the mythology, this union includes Aether, Hemera, the Hesperides, Hypnos, the Moirai, Geras, Styx, and Thanatos.
In Greek literature the name Erebus is also used to refer to a region of the Underworld where the dead had to pass immediately after dying, and is sometimes used interchangeably with Tartarus.
(from Wikipedia)

So here it is. The long, dormant summon series has come back. This is Erebos, the shadow summon. I emphasise on the 'shadow' part here. So I made the concept of a shadow knight. An empty suit of armour controlled by spirits.