Steadfast Wizard: From Heart-Swapping Rat to Dimensional Demon God

This is a magical world, inhabited by numerous wondrous powers and races. Demons, evil gods, ancient gods, monsters, fairies, and other wondrous beings coexist with humanity. Through the power bestowed upon them, humanity gradually ushered in its own era. Among humanity, however, emerged a group of crazed gamblers obsessed with trading with these wondrous beings… They proclaimed… that going all in is a form of wisdom! They firmly believed… that no child cries every day, and no gambler loses every day! They are… legendary wizards! And among these legendary wizards, Isaac is a special case. He doesn't consider himself a gambler, for a simple reason: not knowing the outcome is gambling; knowing the outcome is investment! A 1000% success rate—is that gambling?