Declension table of ?vastya

Neuter	Singular	Dual	Plural
Nominative	vastyam	vastye	vastyāni
Vocative	vastya	vastye	vastyāni
Accusative	vastyam	vastye	vastyāni
Instrumental	vastyena	vastyābhyām	vastyaiḥ
Dative	vastyāya	vastyābhyām	vastyebhyaḥ
Ablative	vastyāt	vastyābhyām	vastyebhyaḥ
Genitive	vastyasya	vastyayoḥ	vastyānām
Locative	vastye	vastyayoḥ	vastyeṣu

Compound vastya -

Adverb -vastyam -vastyāt