This is a tie-up to the article on Buddhist mythology that Ven Sujāto advocated compiling here. In that thread (actually, in one of the links in that thread), Borobodur is mentioned. The upper levels of Borobodur are actually based on the abovementioned Mahāvaipulyanāmabuddhāvataṃsakasūtra, and the pinnacle depicts the last sūtra in the vaipulya, the Gaṇḍavyūhasūtra. Therein at the top is depicted the bodhimaṇḍa with Samanthabhadrabuddha depicted symbolically awaiting the next samyaksaṃbuddha to receive abhiṣeka from the daśadiktathāgatāḥ (Buddhas of the Ten Directions), announcing his (and this is likely from that problematic movement within Buddhism arguing that women are reborn as men before attaining Buddhahood) complete and perfect enlightenment.
Tantric sects believe that their ordination is this very abhiṣeka, initiating, for them, the completion stage of Supreme Buddhahood, if you believe Tantric self-narratives. When the guru, in the context of high guru yoga, places his hands on you, that is the ordination of the daśadiktathāgatāḥ. To quote a prominent tīrthika saying, tvāmamareśvarasyābhiṣiktapūtraḥ, you are the deathless lord’s annointed son.
On the completion stage of Buddhahood it is believed that the practitioner can engage in all sorts of subtle mental states, as well as transform mundane or afflicted dharmāḥ into the pure dharmāḥ of the path. After all, you and sarvabuddhabodhisattvāḥ are pointing out these pure dharmāḥ, that is the principle activity of the Aryans, why not include eating a meal, or even your sex life, as a path object? All of these dharmāḥ are empty anyways, so where is the disparity between the path and saṃsāra? You can see these things argued on, for instance, certain subfora of DharmaWheel.
Therein lies the sectarian polemics at the heart of Mahāyāna-Mantrayāna sectarianism: the Tantrists believe they already have the highest ordination that exists: fellowship with complete Buddhahood, transcending the 10th bhūmi. This is, to put it mildly, wishful thinking, from a non-Tantric POV IMO.