δαῖμον, ὃς ἐμπίτνεις δώμασι καὶ διφυί-
1470κράτος <τ’> ἰσόψυχον ἐκ γυναικῶν
καρδιόδηκτον ἐμοὶ κρατύνεις.
ἐπὶ δὲ σώματος δίκαν μοι
κόρακος ἐχθροῦ σταθεῖσ’ ἐκνόμως
1474ὕμνον ὑμνεῖν ἐπεύχεται <˘¯>
O Fiend who falls upon this house and Tantalus' two descendants, [Note: Agamemnon and Menelaus.]
1470you who by the hands of women exert a rule matching their temper, a rule bitter to my soul! Perched over his body like a hateful raven, in hoarse notes she chants her song of triumph.
— H. W. Smyth
If we read about this in the Gospels we would expect these two women, Helen and Clytemnestra, to be the subjects of a miracle of deliverance from demonic control. But not here, not in Agamemnon. Similar however is the notion that a propensity for evil in human thinking and action can be attributed to influence of agents from the realm of the unseen. Modernism called this the realm of the supernatural but to the ancients it was perfectly natural to think in terms of spirits as agents who influenced human thinking and behavior. In the last fifty years this pre-modern framework has seen a widespread revival and more recently in enormously popular novels and movies.
One of the things I find most rewarding about the study of Attic Tragedy is the psychological and spiritual depth of the character development. The Tragic hero is not a nice guy, he is not a cowboy with a white hat. The hero and villain can be the same character. Tragic women can be borderline psychotic (Electra) or psychopathic (Clytemnestra). The Clytemnestra of Euripides isn't the Clytemnestra of Agamemnon. In terms of the demonic, Sophocles' Electra is a close rival of Clytemnestra of Agamemnon. I know this has been discussed for ages and ages in the critical literature. But it still makes the works worth a close reading in the original language. This is something you might miss out on if you just breeze through the works in a translation.
My first encounter with Clytemnestra was reading William Faulkner but I haven't look at Faulkner for thirty years now.
On this and the response of Clytemnestra:
Clytemnestra approves of the chorus’s new insight into what
has just transpired (1476) and calls the daimon τριπάχυντον,
 terms used in a popular sense.
 a hyper-scholarly article from Spain in english: Aeschylus, Agamemnon 1478–1480
Miryam Librán Moreno, 2009. I picked this up from Duke via Google.