[Note: this subclass is likely not intended as official content: "For the curious, when building stuff for my own campaign I kind of don't care about balance. Anything I can break in design I can counterbreak five times as bad during a session, as needed. Plus, IMO stuff going sideways and weird is why I play the game."—Mike Mearls]
Custom built for clerics of Gruumsh, and perhaps Tiamat.
At each indicated cleric level, you add the listed spells to your spells prepared.
1st level - Inflict wounds, wrathful smite
3rd level - Enlarge/reduce, shatter
5th level - Fireball, lightning bolt
7th level - Ice storm, staggering smite
9th level - Cloudkill, destructive wave
When you choose this domain at 1st level, you gain proficiency with martial weapons.
Starting at 1st level, you can channel divine energy to enter a destructive frenzy. As a bonus action, you gain 5 temporary hit points and a +1 bonus to weapon damage rolls. This benefit lasts for one minute. Once you use this ability, you cannot use it again until you complete a short or long rest.
When you use this ability, you can expend a spell slot to augment its effects. You gain additional temporary hit points equal to three times the slot's level and a bonus to weapon damage rolls equal to half the slot's level (minimum 1). This benefit lasts for one minute.
Starting at 2nd level, you can use your Channel Divinity to channel destructive energy.
As an action, you touch a creature or a an unattended object within reach. A creature must make a Constitution saving throw, taking 5 times your cleric level thunder damage on a failed saving throw and half as much on a successful one. An unattended object takes 5 times your cleric level thunder damage.
Starting at 6th level, your destructive acts fuel further expressions of devastation. If you kill a creature or destroy an object with a weapon attack, you can use your reaction to immediately make one additional weapon attack.
You can use this ability a number of times equal to your Wisdom modifier (minimum 1). You regain all expended uses when you complete a long rest.
Starting at 8th level, you gain the ability to infuse your weapon strikes with divine energy. Once on each of your turns when you hit a creature with a weapon attack, you can cause the attack to deal an extra 1d8 thunder damage to the target. When you reach 14th level, the extra damage increases to 2d8.
8th-level cleric Divine Domain feature (replaces Divine Strike)
In battle, you are blessed with divine might. When a creature takes damage from one of your spells or weapon attacks, you can also deal 1d8 radiant damage to that creature. Once you deal this damage, you can't use this feature again until the start of your next turn.
Starting at 17th level, your spells deliver exceptional power. When you roll damage for a spell, roll twice the listed number of dice. You then choose from among the rolled dice the results you wish to use to determine the spell's damage. You must select dice that match the quantity and type normally rolled to determine the spell's damage.