Benedictioner

This is more of a set of rules akin to those of the Enchantment Rules in DnD rather than an actual, full fledged Feat.
For those experienced in the edicts of their gods words, have the knowledge to lay blessings on items in their name. (Substitute every mention of the word Bless with Curse if necessary for Warlock)

Blessing. This functions about equivalently to Magic Enchantments on items and weapons so to speak, for specific blessings you must have a blueprint for how to apply them. Proficiency in Religion rather than Arcana, but it diverges in that Proficiency in the Tool is simply not necessary. Instead the acquisition of the material component is far more difficult, a true artifact pertaining to your Deity or Oath must be used, or be level 20 in your specific Holy Class.    
When Applying you must roll a Religion Check, using Wisdom/Intelligence modifier for Clerics and Charisma/Intelligence modifier for Paladins/Warlocks. With a DC set by the DM, on a critical fail the artifact or important item and the weapon/item is destroyed, on a failure the weapon/item is destroyed, on a success the Blessing is permanently applied to the item and the Divine Artifact used will be recharging its divinity for a time(Chosen by DM, advised to be at-least 100 years) 
Relic Integration, in the same way that sometimes enchanting an item means using a specific material in the items creation, having an Artisan create the item using the Divine Relic as a Component lowers the DC for success exponentially, you are however placing the Relic in more danger as a regular failure on the Blessing Ritual will destroy the item, divine relic included..

(An item can theoretically be both Enchanted and Blessed at the same time, but both sides would take a -20 modifier to their roll when applying the enchantment/blessing after the first has been applied)