In games I write, I tend to be pretty uhhhhhhhhhhhhhhhh Reddit neckbeardy about religion (despite being a somewhat religious person). There are powerful religious institutions in the real world. They can't all have a direct line to cosmic truth, it's mutually exclusive. Having churches and priests be important in the same way as they are in the real world is more interesting to me than having a strange plurality of quasi-polytheism ala D&D. This is all to say, I rarely write/run games with traditional clerics or where divine truths are knowable. 

There are a few early adopters to His Majesty the Worm who saw this as a gap to be filled and did a bully job filling it (Paths of the Devoted is a published example). Here's my take on doing a more trad fantasy cleric for the Worm. 

This path has a real focus on Camp Actions, where they pray, sing liturgy, chant stories from the canon, and minister to their flock (the guild). Members of the Path of the Grail have an unprecedented mastery of fate as they can manipulate the minor arcana deck in new ways.

Note: If used for your games, the intention is for this path to replace the Path of Cups from the His Majesty the Worm core book.

Path of the Grail

Anybody can be shown the lesser mysteries of Mythrys, but only the Secret Pope knows the last mystery, and only the four members of the highest initiation even know who the Secret Pope is. As such, the identity of the Secret Pope is a thing of much conjecture. Some say it is a child and that the final mystery is “innocence.” Some say it is a corrupt and bloated vampire, and that the final mystery is “eternal life.” Some say it is His Majesty the Worm; nobody speculates as to what He knows.

Common motifs: animal-loving cleric, epicurean friar, battle nun, false prophet, idealistic templar

Art by Fernando Salvaterra

Grail talents

Blessing

As the High Chant talent from the core book, page 79, except you must say a grace before you break bread. 

Counsel

As the talent of the same name from the core book, page 78.

Lay on Hands

You may provide healing to your companions. You can expend a vial of holy water to Heal someone (p. 12). This effect cannot be used to clear the Stressed condition.

Additionally, this talent gives you a new Camp Action: Lay on Hands. When you use Lay on Hands, you give everyone in the guild (including yourself) 1 free charged Bond to be spent during the Recovery step of this Camp Phase. If you expend a vial of holy as part of this action, adventurers who used the Rest and Recovery action gain 4 burned charges for the purpose of recovering from an Affliction (p. 137).

Magic of the Welkin

As the talent of the same name from the core book, page 82. 

Omen

This talent gives you a new Camp Action: Prognosticate. When you Prognosticate, draw the top three cards from the top of the minor arcana deck. Put one card back on top, put one card on the bottom of the deck, and discard one card. 

Additionally and optionally, you may make a pact. When you make a pact, charge one religious icon that you're carrying for each pact made. 

You may pray over a charged religious icon you're holding in your hand. This is equivalent to casting a spell. The spell cast is determined by the GM, using their judgement for whichever spell would be most beneficial for the guild at the present time. 

Each religious icon may be charged only once. Your pact lasts until broken or until the spell is cast. Icons remain charged until the spell is cast or until you break the pact. If you break the pact, draw on the maleficence table (Appendix A, p. 201).

Pacts:

• Forego edges: You may not carry a blade of any kind, nor may you shave or cut your hair. Bladed weapons, cutlery, hatchets, shears, razors, etc. are all forbidden to you. 
• Poverty: You may not carry more than 25g.
• Ritual purity: You may not touch or handle the dead. You may not take the life of a (demi)human. You may not drink wine or strong drink, nor handle vinegar. 
• Self-mortification: As the pact in the core book, page 83.
• Self-mutilation: As the pact in the core book, page 83.
• Silence: As the pact in the core book, page 83.
• Verity: As the pact in the core book, page 83.

Turn Undead

When you use a religious icon to ward away the undead (core book, p. 168), you gain an additional effect determined by the number of face cards (page, knight, queen, king) in the minor arcana discard pile.

# of Face Cards	Effect
1	Your religious icon glows, casting bright light.
2	Gain favor to the turn undead attempt.
3	Undead up to 2 Health suffer a Critical Wound instead of being Displaced.
4	Undead up to 4 Health suffer a Critical Wound instead of being Displaced.
5+	Undead up to 7 Health suffer a Critical Wound instead of being Displaced.