According to Tertullian, Adv. Marc. V 6,11: 'homo et res et opus et imago et similitudo et caro per terram et anima per afflatum creatoris ist'. Hence, Marcion had read Gen. 1:26 in its entirety (imago et similitudo) as a simile of the creator god. What he created, he body, but also the substance that he breathed into the created body of man, was the creator's spirit and, therefore, the soul derived from the creator (see Tert., Adv. Marc. II 5,1: 'immo et substantiam suam, per animae scilicet censum'). The soul is the subject of sin which follows temptations and leads the body to perish. The soul itself, therefore, would have been condemned to perish with the body.
Here, however, Marcion's soteriology sets in. Barbara Aland who is the sole scholar who has looked into this soteriological process more deeply, and the only one who has somehow understood Marcion ('Marcion: Versuch einer neuen Interpretation': ZKG 70, 1973, 420-47), does not carry her thoughts through to the end, but sees Marcion's concept breaking down at the problem: if the soul, too, was the creator's work - why then should the supreme God of Love care about human beings? Why not leave it to rest, as he lets the body and the world of the creator perish? Why, according to Marcion, does he promise human beings a true substance of angels ('vera substantia angelorum', Tert., Adv. Marc. III 9,4)? There is no logical breakdown, as she assumes (ibid. 443), but Marcion only follows vigorously his main theory - namely that all actions of the God of Love build on and use the products, names and stories of the creator god, in order to show the unexpectedness of Love's action. Where creatures see a breakdown of logic or system or theology - trained by our perception that was guided by the scriptures of the creator god, as soon as one realizes the revelation of the God of Love, such breakdown turns out as proofs of Love. Whereas there was no reason whatsoever to save the soul, as it was utterly a created substance by the creator god, the God of Love in his kenotic act of salvation on the cross makes the gracious gift of a true angelic substance and makes the saved human beings, what the Lord himself has been, an angel with his new angelic message (= eu-angelion).
PS: sorry for my relatively long absence from blogging - but I wanted to finish my new book on 'Marcion and the Dating of the Synoptic Gospels'. And, nice to tell you, yes, it is finished and awaits publication. As soon as I know more about the publishing process, I'll let you know.