There is no substantial proof of any other deity other than Allah and those who deny it are clearly ignorant of the very truth that is in front of them. The Holy book (Quran) is the ultimate proof of Allah’s power and no one else can be worshipped other than Him.
“Or have they taken gods besides Him? Say, [O Muhammad], “Produce your proof. This [Qur’an] is the message for those with me and the message of those before me.” But most of them do not know the truth, so they are turning away.”
Quran(Surah Al-Anbiya, 24)