Declension table of ?viṣamantra

Masculine	Singular	Dual	Plural
Nominative	viṣamantraḥ	viṣamantrau	viṣamantrāḥ
Vocative	viṣamantra	viṣamantrau	viṣamantrāḥ
Accusative	viṣamantram	viṣamantrau	viṣamantrān
Instrumental	viṣamantreṇa	viṣamantrābhyām	viṣamantraiḥ viṣamantrebhiḥ
Dative	viṣamantrāya	viṣamantrābhyām	viṣamantrebhyaḥ
Ablative	viṣamantrāt	viṣamantrābhyām	viṣamantrebhyaḥ
Genitive	viṣamantrasya	viṣamantrayoḥ	viṣamantrāṇām
Locative	viṣamantre	viṣamantrayoḥ	viṣamantreṣu

Compound viṣamantra -

Adverb -viṣamantram -viṣamantrāt