To the Christians (or other theists) out there, what if Satan/Great Evil took God's position, permanently?

The reason satan is who and where he is, he already tried to make himself 'greater' than God. Since it didnt work the first time, and satan is eternally in Hell for it, It'll never happen again. 'If' satan was somehow more powerful than God, after knowing the evilness and hatred he represents, he comes to kill, steal and destroy. Or could be the anti-christ who will lie and confuse many. Who would believe in a magnificent reward in an afterlife, from his candy coated lying lips? Except non-believers of God? Since there's more than the 10 Commandments to read, including numerous other laws, I'll still stay with God. So glad this is a "what if" question.