Bṛhattantrasāra - yoginīsādhana

Bṛhattantrasāra - yoginīsādhana

athātaḥ sampravakṣyāmi yoginīsādhanottamam
sarvārthasādhanaṃ nāma dehināṃ sarvasiddhidam
atiguhyā mahāvidyā devānāmapi durlabhā 53
yāsāmabhyarccanaṃ kṛtvā yakṣeśo.abhūddhanādhipaḥ
tāsāmādyāṃ pravakṣyāmi surāṇāṃ sundarīṃ priye
asyā abhyarcanenaiva rājatvaṃ labhate naraḥ 54

53. Now I will tell [about] the highest(ut-tama-) practice(sādhana-) of female deities(yoginī-)called(nāma) the all purposes practice(sarvārthasādhana-) that is conferring powers(siddhi-) to humans(dehin-).
This extremely secret(atiguhya-) great science(mahāvidya-), even for the gods(deva-) [is] difficult to obtain(durlabha-).


54. I will tell(pravakṣyāmi) to Sundarī, oh dear(priyā-), [that] of whose(yā-) worship(abhyarcchana-) he is doing(kṛtvā) [he] becomes(abhūt) the master over demons(yakṣeśa-) that guard the treasures of these(tāsām) goddesses(surā-).

By the very(eva) worship(abhyarcchana-) of her(asyā) the man(nara-) obtain(labhate) sovereignity(rāja-tva-).

I am not very happy with the verse 54, so please comment on it. I had troubles fitting Accusative of Sundarī in it.