I suppose, they are not that effective. Because in it power homeworld it was a prize of victory in battle, but there Champion again have become a contender, while gods with their authority’s are steel “ruling champions”.
You know this whole conflict would have gone better if he trained his destruction. I guess just any training would have been good. It's been forever since he actually developed his skill set.
Kronos was a good challenge for Will. Honestly DxD power structure is nowhere close to Nasuverse broken system. If Will can't even last an hour against Goetia. There's no way he can matched the likes of other entities in there such as an Ultimate One.