• vijitya — conquering
  Gerund — 'having conquered'. Note that the conquest is preliminary, not the point. The Rājasūya is the point; victory is preparation.
• nṛ-patīn — the kings
  Compound accusative. The kings of the earth must be brought under one suzerain before the sacrifice can be offered — Vedic dīkṣā for a samrāṭ requires unrivalled sovereignty.
• sambhārān — the paraphernalia
  Accusative plural. Sacrificial materials — ghee, grains, gold, soma vessels. Even after conquest, the work is not over; the sacrificial details must be gathered with care.
• mahā-kratum — the great sacrifice
  Compound. Mahā here is not loose — the Rājasūya is technically a mahā-kratu, requiring years of preparation and a vast ritual establishment.

Before a coronation the courtyard must be swept and the lamps lit. Before the Rājasūya — the cosmic coronation of dharma — the earth itself must be swept clean of unsubmitted kings. Conquest here is sweeping, not greed.