This is not the original present aspect of the second aorist e)/tuxon (epsilon 3344), which was teu/xw (see tau 435). It is derived from the aorist by the infix nan and served as an alternative present tense to indicate that one is already in a deliberate process of achieving (see Chantraine, Gr. hom. 315-16), whereas teu/xw indicates that one is still engaged in preparation. Like the second aorist from which it is derived, it governs the genitive. See the fuller accounts at tau 435 and in Villard Leglay’s dissertation, cited there.
Homer uses it twice, both times in the imperfect, in a sense that seems at first passive. At Odyssey 14.231, in the lying tale of Odysseus, he tells how he has raided cities with his ships and “much booty came my way” (moi ma/la tu/gxane polla/), i.e. was successfully acquired by me as a result of these raids. In the battle at Iliad 11.74, “Strife alone of the gods was present beside the fighting men” (paretu/gxane marname/noisin). These senses are also found in Homer for the aorist. Note especially Iliad 11.684, virtually identical to 11.74; cf. Odyssey 14.334 = tau 291, phi 13.