Declension table of ?dvayu

Masculine	Singular	Dual	Plural
Nominative	dvayuḥ	dvayū	dvayavaḥ
Vocative	dvayo	dvayū	dvayavaḥ
Accusative	dvayum	dvayū	dvayūn
Instrumental	dvayunā	dvayubhyām	dvayubhiḥ
Dative	dvayave	dvayubhyām	dvayubhyaḥ
Ablative	dvayoḥ	dvayubhyām	dvayubhyaḥ
Genitive	dvayoḥ	dvayvoḥ	dvayūnām
Locative	dvayau	dvayvoḥ	dvayuṣu

Compound dvayu -

Adverb -dvayu