Is there any way I could see a list of ALL challenger loot items on Subeta? I can't seem to find an option anywhere... Thanks.

Challenger loot is rarity 170, so if you go to the Item Directory and use the rarity sort feature, you can see all challenger loot items.

You can also see this on SubetaLodge, where if you click the item, the notes will tell you which challenger drops the item.

Thanks so much