The Resplendent Prism is a Bauble that sits in the Amulet slot. This Bauble will add levels to random enchants on the items you are wearing or have equipped in your main or off hand. The Prism will add up to 3 different (random) enchant levels. This can also apply to enchants added by other mods. It is also very important to know that levels are added to EXISTING enchants.
The Resplendent Prism uses Curios instead of Baubles in 1.15.2 and up. Curios uses necklaces instead of amulets.
The enchants are randomly rolled when you put the Prism into your inventory:
The Prism can boost up to three enchants and can add up to +2 levels on a single enchant. The Prism can also boost itself:
As you can see above, you would get +1 to Existing Burnerang and +1 to all existing Enchants, so you could have up to +3 to Burnerang (the original Burnerang enchant, +1 to Burnerang and +1 to all enchants). The Prism will also allows you to go beyond enchanting limitations. It can also be rerolled via the Celestial Altar.