Ainz Ooal Gown is one of the stronger main characters out there as his stats were maxed out right from the start. He could give many fighters a run for their money but not Bass. Bass is still known as the ultimate character in media for good reason. He never surrenders and never backs down. His power is absolute and a few Darkness Overloads will end this. Ainz Ooal Gown may not expect that he would lose to darkness, but such is the irony of power. Bass wins.