Sing The Corrosion

You could probably use the way this spell works as a template for cleric spells specific to any given god. I might've done a d20 table but Vorn just doesn't have a very diverse portfolio.

This version is for version of D&D with 9 cleric spell levels but it's easy to modify.

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Wrath of Vorn 1 thru Wrath of Vorn 9
Level: 1-9--Cleric must choose spell level when preparing, like "I take one Wrath of Vorn 5 and 2 Wrath of Vorn 6's"
Range: 40 feet (see also below)
Area of Effect: 1 target (also see below)
Duration:  One fight or ten rounds, whichever ends first
Saving Throw: Not usually

Roll d6 when spell is cast and consult the following table, comparing the die roll to the chosen level of the spell:

Over the Wrath's chosen spell level: Rusts one targeted object (or human-sized area of a large object) beyond use. Living things and magic items get a save.
Equal: As above plus any metal the creature is wearing constricts it for cleric's level damage per round until removed.
Under by 1: Creature vomits rust-poisoned water on all allies within 10 feet, the creature is helpless for a round and the allies all take cleric's level poison damage.
Under by 2: All attacks with anything metal directed at target automatically hit for one round.
Under by 3: All metal on target rusts beyond use, living things and magic items do not get a save.
Under by 4: Victim throws self in front of the largest metal item in sight, praying before it, heedless of all danger for 2 rounds.
Under by 5: Iron vines grow from inside the target's body, lashing it to the nearest piece of anchored metal (whatever it may be), creeping overland to find an anchor point at 10 feet per round. The victim must save (dragon breath or dex) to avoid being anchored in any round the vines reach a suitable tether point. Otherwise the vines act as a (no save) Slow spell.
Under by 6: All of the above on one target or any one of the above on up to 10 targets.
Under by 7: Any result up to #5 on one target, effect is permanent.
Under by 8: Any result up to #5 on caster level number of targets, effect is permanent.

If this spell is delivered by touch then magic resistance does not apply.

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*This is the second time I've used a picture from this "torvenius" on DeviantArt so I better give credit.