Declension table of ?siddhimantra

Masculine	Singular	Dual	Plural
Nominative	siddhimantraḥ	siddhimantrau	siddhimantrāḥ
Vocative	siddhimantra	siddhimantrau	siddhimantrāḥ
Accusative	siddhimantram	siddhimantrau	siddhimantrān
Instrumental	siddhimantreṇa	siddhimantrābhyām	siddhimantraiḥ siddhimantrebhiḥ
Dative	siddhimantrāya	siddhimantrābhyām	siddhimantrebhyaḥ
Ablative	siddhimantrāt	siddhimantrābhyām	siddhimantrebhyaḥ
Genitive	siddhimantrasya	siddhimantrayoḥ	siddhimantrāṇām
Locative	siddhimantre	siddhimantrayoḥ	siddhimantreṣu

Compound siddhimantra -

Adverb -siddhimantram -siddhimantrāt