Declension table of ?manastva

Neuter	Singular	Dual	Plural
Nominative	manastvam	manastve	manastvāni
Vocative	manastva	manastve	manastvāni
Accusative	manastvam	manastve	manastvāni
Instrumental	manastvena	manastvābhyām	manastvaiḥ
Dative	manastvāya	manastvābhyām	manastvebhyaḥ
Ablative	manastvāt	manastvābhyām	manastvebhyaḥ
Genitive	manastvasya	manastvayoḥ	manastvānām
Locative	manastve	manastvayoḥ	manastveṣu

Compound manastva -

Adverb -manastvam -manastvāt