The Steady Wizard: From Heart-Switch Rat to Dimensional Demon

This is a magical world. In this world, there are many magical powers and races. Magical beings such as demons, evil gods, ancient gods, demons, goblins, etc. coexist with humans in this world. With the power granted by them, humans gradually ushered in their own era.
Among humans, there appeared a group of crazy gamblers who were keen on trading with magical beings...
They claimed...
Show is a kind of wisdom!
They firmly believe...
No child cries every day, and no gambler loses every day!
They are...
Legendary wizards!
Among the legendary wizards, Isaac is a special existence. He does not think he is a gambler. The reason is very simple. Not knowing the result is gambling, and predicting the result is investment!
1000% success rate, is that called gambling?