How isn't Mark of the Marcosians 'Mystic Mark'?

And in addition to these men he says that there was also another that lived in that age, Marcus by name (Μάρκος αὐτῷ ὄνομα), who was remarkably skilled in magic arts (μαγικῆς κυβείας ἐμπειρότατον). And he describes also their unholy initiations (τελετὰς μυσεράς) and their abominable mysteries (μυσταγωγίας ἐκφαίνων) in the following words: "For some of them prepare a bridal chamber (νυμφῶνα) and perform mystagogery (μυσταγωγίαν) with certain forms of expression addressed to those who are being initiated (τελουμένοις), and they say that it is a spiritual marriage (πνευματικὸν γάμον) which is celebrated by them, after the likeness of the marriages above (τῶν ἄνω συζυγιῶν). But others lead them to water, and while they baptize them they repeat the following words: Into the name of the unknown father of the universe, into truth, the mother of all things, into the one that descended upon Jesus. Others repeat Hebrew names in order the better to confound those who are being initiated (τελουμένους)." [Eusebius Church History 4.11.5]

[Mark] brought in certain sayings of which he knew the interpretation would, as a mystagogue (μυσταγωγήσειν), lead the hearers into the shrine (ἄδυτον) of that truth hidden by seven veils. Thus, in sum, he prepared matters, neither grudgingly nor incautiously, in my opinion, and, dying, he left his composition to the church in Alexandria, where it even yet is most carefully guarded, being read only to those who are being initiated into the great mysteries (τοὺς μυουμένους τὰ μεγάλα μυστήρια) ... [T]he mystic Gospel brings the following material word for word ... "And after six days Jesus told him what to do, and in the evening the youth comes to him, wearing a linen cloth over his naked body. And he remained with him that night, for Jesus taught him the mystery of the Kingdom of God."[Clement of Alexandria, Letter to Theodore]