Koti dandavata obeisances to Sri Hari Hara, appearance of the combined forms of Sri Vishnu and Mahadeva. He resides over and protects the Vaisnava holy dhama Godrumadvipa and Sri Sri Bhubaneswara/Jagannatha Puri.
"One who says he is My devotee, but has no devotion for Mahadeva, he is not actually my devotee" Lord Vishnu, Sri Hari.
"One who is my devotee but not a devotee of Lord Vishnu is not in reality my devotee" says Lord Hara deva, Siva Sambhu.
In the Brahma-vaivarta purana, Lord Shiva spoke to the demigods, the devas, about the glories of chanting Sri Krishna's names:
adhunaa pancha-vaktrena yan naama-guna-kirtanam
gaayan bhramaami sarvatra nishprhah sarva karmasu
With my five faces I chant His name and qualities while I wander everywhere without involving myself in anything
matto yaati ca mrtyush cha yan naama-guna-kirtanam
shaasvaj japantam tan naama drshtavaa mrtyuh palaayate
Because I constantly chant His name and qualities, death does not touch me. Death runs away from that person who chants his name.
sarva brahmaanda samhartaapy aham krtyunjayaabhidhah
schiram tapasaa yasya guna-naamaanu-kirtanaat
By reciting His name and qualities while performing my austerities for a long time, I have achieved the power to destroy all the universes and have conquered even death.
vihvala digambaranirantara kahe shiva murli krishna dasa
Immersed in love of Krishna, an agitated Shiva constantly chants, 'I am Krishna's servant.'