The zeal domain is held by no specific god. Rather, the zeal domain is taken up by clerics who serve their deity with undying fervor. These warrior-clerics, also known as zealots, are known to be a terrifying force in battle, and able to defy even death itself to destroy the enemies of their god.

Level 3: Consuming Fervor

Starting at 3rd level, you can use your Channel Divinity to channel your zeal into unchecked ferocity. When you roll Fire or Thunder damage, you can use your Channel Divinity to roll an additional dice of damage for each dice that rolls the highest number or one less (for example, a 5 or a 6 on a d6). The maximum number of these dice you can add to the roll’s damage equals your spellcasting ability modifier.

Level 3: Zeal Domain Spells

Your undying dedication ensures you always have certain spells ready. When you reach a Cleric level specified in the Zeal Domain Spells table, you thereafter always have the listed spells prepared.

Due to capitalism, you have to add the Ashardalon's Stride, Destructive Wave, and Thunderous Smite spells manually, sorry.

Zeal Domain Spells

Cleric Level	Prepared Spells
3	Magic Weapon, Searing Smite, Shatter, Thunderous Smite, True Strike
5	Ashardalon's Stride, Fireball
7	Fire Shield (warm shield only), Freedom of Movement
9	Destructive Wave, Flame Strike

Level 3: Zealous Training

At 3rd level, your divinely dedicated training with weapons allows you to use the mastery properties of two kinds of weapons of your choice with which you have proficiency, such as Longswords and Javelins.

Whenever you finish a Long Rest, you can change the kinds of weapons you chose. For example, you could switch to using the mastery properties of Halberds and Flails.

Level 6: Relentless Fervor

Starting at 6th level, you can attack twice instead of once whenever you take the Attack action on your turn.

In addition, you can cast one of your Cleric cantrips that has a casting time of an action in place of one of those attacks.

Level 17: Blaze of Glory

When you are reduced to 0 Hit Points, you can choose to go out in a blaze of glory. Each creature of your choice within a 30-foot Emanation makes a Dexterity saving throw. On a failed save, a target takes 5d10 Fire damage and 5d10 Thunder damage, or half as much on a successful one. If the creature that reduced you to 0 Hit Points is within the Emanation, it has Disadvantage on the save.

Once you use this feature, you can’t use it again until you finish a Long Rest.