Succubus
A Succubus is a female demon believed to abuse men (the male demon is the incubus). However, Maria Valtorta uses Succubus as a synonym for "concubine," which is actually the original Latin etymological meaning (succuba). In the context of the episode, it could be translated as "minion," a connoted term, or "spirit devoted to." It would be interesting to investigate whether this meaning corresponded to the usages of the time, which we have not yet succeeded in establishing.
The episode
In GRM 575.10-11, Jesus dialogues with Judas, who has become rebellious and impermeable to advice as well as orders. This dialogue, in which Judas often interrupts Jesus, is one of the last attempts to To Save Judas from the fate he has chosen.
"«You must realise, Judas, that to appear before the Lord with an unclean spirit, such as you have, does not honour Him, but it offends Him. First it is necessary…"»«Why do You not purify and cure me, then?» asks Judas, and he already sounds hard and indocile.
«I will not cure you! When a man is ill he seeks cure by himself, unless it is a child or a fool who are devoid of will-power…»
«Treat me as such. Treat me as a fool and see to it, without my being aware of it.»
«It would not be just because you can use your will-power. You know what is good and what is evil for you. And My curing you would be of no avail without your will to remain cured.»
«Give me such will as well.»
«Give you it? So should I impose a goodwill on you? And your free will? What would it become? What would your ego of a man, of a free creature be? Dominated?»
«As I am dominated by Satan, I may also be dominated by God!»
«How you hurt Me, Judas! You pierce My heart! But I forgive you what you do to Me… Dominated by Satan, you said. I did not mean such a dreadful thing…»
«But You were thinking of it because You know that it is true, and because You are aware of it, if it is true that You can read the hearts of men. If it is so, You know that I am no longer free to do what I like… He has seized me and…»
«No. He approached you, tempting you, testing you, and you received him. There is no possession if at the beginning there is no assent to some satanic temptation. The snake introduces his head between the bars closely placed to defend hearts, but he would not be able to enter if man did not widen a passage to admire his alluring aspect and listen to and follow him… Only then man becomes dominated, possessed, because he wants it. God also darts the very kind lights of His paternal love from the heavens, and His lights penetrate us. Or rather: God, to Whom everything is possible, descends into the hearts of men. It is His right. Since man knows how to become a slave dominated by the Dreadful one, why does he not know how to become a servant of God, nay a son of God, and he drives away his Most Holy Father? [...] »"[1]