Of the three Script types, Signature Scripts have the most interesting functionality, as the secondary effects they provide are often the primary reason for using that Grimoire in the first place and they have different implementations depending on the specific Grimoire they are scribed to. Since we haven't yet received a Scribing Grimoire for the Werewolf skill line, I'd like to take a moment to walk through all 20 available Signature Scripts and talk about how each could be applicable for a Werewolf Grimoire, as well as what kind of ability would make the most sense in that context.
Note that while we
could receive brand new Scripts with the introduction of new Grimoires, I expect that the existing Scripts will be reused and repurposed, like how Cavalier's Charge was formerly only used by Trample before Banner Bearer was added. It would be cool to see a new Signature Script exclusively used by Werewolf and Vampire Grimoires, though, like maybe something that reduces your bounty when seen activating Criminal Act skills.
1. Anchorite's Cruelty

This is currently exclusively used by the Soul Magic Grimoires, Soul Burst and Wield Soul, to deal Execute-scaling Oblivion damage over time. I don't think it's thematically appropriate for a Werewolf Grimoire, as it consumes Soul Gems to gain its effect.
2. Anchorite's Potency

Like the above, this is also exclusive to the Soul Magic Grimoires, Soul Burst and Wield Soul, to generate Ultimate. This wouldn't be fitting for use on a Werewolf Grimoire for the same reason as above.
3. Assassins Misery

On Elemental Explosion and Trample, this applies three status effects to enemies, while on Traveling Knife, it gives 100% increased status effect chance on enemies. I think that a Werewolf Grimoire which is a martial attack could use this Script to apply Hemorrhaging, Sundered, and Concussion to the enemy, like how Trample works. Maybe this Werewolf Grimoire could be like the old Piercing Howl ability, or some other kind of attack animation where the enemy gets hit really hard, to make the Concussion status effect make sense. The Werewolf skill line is already full of Hemorrhaging and Sundered procs, so those would be a natural fit on this Grimoire.
4. Cavalier's Charge

On Trample, this increases the damage as your mount travels outward, while on Banner Bearer, it increases your WD/SD based on your movement speed. To me, this description reads as something like Claw Fury, which increases in damage per stack of Blood Hunger while generating stacks of Blood Hunger as the channel continues, or as something like Ritual of Retribution, which is a ground effect that increases damage by 12% per tick. Maybe a Werewolf Grimoire could be a channel or a ground effect which would increase in damage with this Script?
5. Class Flourish (formerly known as Class Mastery)

On most Grimoires, the effect of this Script is the same, but on Banner Bearer, it is tweaked slightly to coincide with the passive activation nature of that Grimoire. Arcanist's Class Flourish on Banner Bearer was given a secondary effect, where it will only generate Crux if you have none, and will generate Ultimate if you already have Crux and are in combat.
Since Werewolves cannot slot or use Class abilities, certain tweaks should be made if this is to be available on a Werewolf Grimoire:
- Nightblade: No change necessary
- Dragonknight: No change necessary
- Sorcerer: It might be worth specifying that you only get access to pets via the Pack Leader morph. This would theoretically work just fine regardless.
- Templar: Thanks to Class Mastery passives (specifically Steadfast Candescence) it is now possible to proc Sacred Ground while in Werewolf form, so no change is necessary here.
- Warden: No change necessary
- Necromancer: No change necessary
- Arcanist: Since it is not possible to consume a Crux while in Werewolf form aside from letting the Crux buff expire, this would need to be tweaked like it was on Banner Bearer. Maybe this generates Ultimate if you are at 3 Crux, or maybe (given we can generate Crux via Arcanist Class Mastery passives, specifically Ink-Scribe's Verve) it instead spends Crux. It could generate Crux until it reaches 3 Crux, then spend them all on the next cast of the Werewolf Grimoire. Maybe it converts Crux into Blood Hunger, since those two mechanics are similar in function.
6. Crusader's Defiance

On Vault, Torchbearer, Soul Burst, and Smash, this Script removes snares and/or negative effects. On Mender's Bond and Smash, it grants immunity to snares, immobilizations, or disabling effects. On Banner Bearer, it reduces the effectiveness of snares. On a Werewolf Grimoire, since the Werewolf skill line naturally has no purge or snare reduction, this would be a very useful Script. I'd personally like to have a snare reduction and negative effect purge, but temporary immunity to snares and immobilizations would be great, too!
7. Druid's Resurgence

On Elemental Explosion, Mender's Bond, Smash, Torchbearer, Vault, and Wield Soul, this Script directly restores resources, while on Banner Bearer and Shield Throw, it grants recovery stats. The Werewolf skill line has a few sources of Stamina restore (such as Feral Pounce/Carnage and Hircine's Bounty) but none for restoring Magicka back. Most likely, a Werewolf Grimoire utilizing this Script would restore Stamina back, to emphasize the need to build into Magicka Recovery by other means. I think it would be fun if this Script on a Werewolf Grimoire restored resources for every enemy hit, like Elemental Explosion, if the ability is meant to be a cleave ability like Bloodclaws. I could definitely see a gradual Stamina restore over time (like Smash) being the implementation, though.
8. Fencer's Parry

Shield Throw, Smash, and Traveling Knife all deflect the next direct damage made against you within 3 seconds, which occurs only once every 3 seconds. Given how these other Grimoires are melee-oriented (they are for One Hand and Shield, Two Handed, and Dual Wield) I can imagine this would mesh well with Werewolf's melee-oriented playstyle. I've never personally used this Script, but I can see how a melee brawler would like to have it.
9. Gladiator's Tenacity

Oddly, this Script is only used by the two Guild Grimoires, Torchbearer and Ulfsild's Contingency, which each reduce your damage taken by a percentage that is inversely proportional to its duration. I'm not exactly sure that a Werewolf Grimoire needs this, but as a melee-oriented playstyle without much mobility, it would come in handy regardless.
10. Growing Impact

Exclusively used by Ulfsild's Contingency, this Script creates a ground effect for 10 seconds that continuously applies the Affix Script to enemies or allies within. Since this adds "enhanced buff and debuff application", we might expect this to make the Affix Script on a Werewolf Grimoire to be applied while slotted and/or while transformed, without the need to cast the ability for that buff, since many of Werewolf's major/minor buffs function that way. Or, maybe the Werewolf Grimoire Affix Scripts just have that "while slotted" functionality baked in.
11. Hunter's Snare

Used by Elemental Explosion, Mender's Bond, Soul Burst, Torchbearer, Trample, Traveling Knife, Ulfsild's Contingency, and Vault, this Script reduces the Movement Speed of enemies. In the case of Trample, it also applies caltrops which deal Physical Damage every second. This Script is by far the most thematically appropriate for a Werewolf Grimoire, both in name and in functionality. The Werewolf skill line does not have a snare, but as a melee-oriented "hunter" playstyle, this Script absolutely should be on a Werewolf Grimoire that is a martial attack, to keep enemies in melee range. While I would've expected a snare on Carnage or Gnash, I could see a snare being put on this Werewolf Scribed skill if it does an action that would look like it would snare the target, like a bite or claw slash to the legs.
12. Immobilizing Strike

Used by Elemental Explosion, Smash, and Trample, this Script immobilizes enemies for 3 seconds. I could see this being put on a Werewolf Grimoire for the same reasons as above. In the case of immobilizing the target, this might be more thematic on a Werewolf Grimoire that would look like a stun, like maybe if the old Piercing Howl ability was made into a Werewolf Grimoire, getting hit by that projectile might temporarily immobilize you.
13. Knight's Valor

On Mender's Bond, this increases the block amount and reduces the block cost by 8%, while on Shield Throw, this deals Physical Damage and bashes the enemy. On a Werewolf Grimoire, since Werewolves do not get Weapon Passives and thus do not get One Hand and Shield blocking passives like Fortress, this really should have a similar implementation to Mender's Bond. Werewolf tanks rely on outside sources for Block Mitigation, like the Granny's Eel Pie food, but having a Werewolf Grimoire that can help improve their tanking would be a really nice improvement.
14. Leeching Thirst

Used by Smash and Traveling Knife, this Script heals you for a percentage of the damage done. Given that Werewolf has several lifesteal abilities like Rip and Tear and Bloodclaws, this Script would be a perfect fit for the Werewolf Grimoire. Maybe it changes whether it scales off of your damage done or your Maximum Health, depending on the Focus Script, e.g. selecting the Taunt Focus Script changes Leeching Thirst to scale off of Health instead.
15. Lingering Torment

Used by Elemental Explosion, Shield Throw, Smash, Soul Burst, Torchbearer, Trample, Traveling Knife, Ulfsild's Contingency, Vault, and Wield Soul, this Script adds a damage over time component which matches the damage type of the Focus Script. On a Werewolf Grimoire, assuming it's a martial attack, we would likely only get to pick between Physical and Bleed, so those would be the damage types for the Lingering Torment Script. We might also get to use Disease Damage again. If the Werewolf Grimoire is an area effect (such as a skill which calls upon Hircine's power in a way similar to Hircine's Bounty) then it might get to use other damage types never before seen in the Werewolf skill line, like Poison or Magic.
16. Sage's Remedy

Used by Banner Bearer, Mender's Bond, Shield Throw, Smash, Soul Burst, Ulfsild's Contingency, Vault, and Wield Soul, this Script just adds a healing over time effect. Since Werewolf does not have a proper heal over time effect (the self heal from Hircine's Bounty is direct, the lifesteal from Bloodclaws and Rip and Tear are direct, and the healing from Insatiable Hunger is also direct) there is no source of healing over time in the Werewolf toolkit. This Script would be very useful for sourcing a proper healing over time effect from the Werewolf skill line, which would let us use certain sets we couldn't use before.
17. Thief's Swiftness

Banner Bearer uses this Script to reduce the cost of Sprint. Shield Throw uses it to allow you to pass through enemies. Trample uses it to increase the Movement Speed of you and your allies in an area. And Vault uses it to remove a stack of Roll Dodge penalty and reduce fall damage taken. Given that Werewolves are agile creatures, I think this Script should increase your own Movement Speed when scribed to a Werewolf Grimoire.
18. Warmage's Defense

Used by Banner Bearer, Elemental Explosion, Mender's Bond, and Traveling Knife, this Script applies a damage shield. While it would be useful to have an in-kit damage shield, it's not necessarily thematic to Werewolf. Maybe this could be justified if it was tied to a Werewolf Grimoire that called upon Hircine's power, but otherwise this wouldn't make sense to put on a Werewolf Grimoire that's just a martial attack.
19. Warrior's Opportunity

On Torchbearer, this increases damage done to enemies afflicted with disabling effects. On Trample, this increases the damage per enemy hit. On Traveling Knife, this causes enemies to take more Martial damage. And on Ulfsild's Contingency, this increases the damage done of the next direct damage attack by 2000. For a Werewolf Grimoire, I'd like to see an implementation similar to Traveling Knife's implementation, where enemies take more damage from Werewolf or Martial attacks for a duration.
20. Wayfarer's Mastery

In general, this Script applies some effect relating to the skill line this Grimoire is found in. If there's any particular reason to want a Werewolf Grimoire, it's to use this Script with it!
Here are a few ideas for this Script as it would relate to each Werewolf passive:
- Insatiable Hunger
- You count as being a Werewolf Berserker for Insatiable Hunger, causing each tick to activate Fury generation.
- Master of the Chase
- Increases your Movement Speed and the Stamina your Heavy Attacks restore.
- Heavy Attacking now restores both Magicka and Stamina, the amount evenly split between them.
- Blood Rage
- Increases the amount of Fury you generate by 15.
- Generating Fury also generates 3 Ultimate.
- Feral Cruelty
- Increases your Weapon and Spell Damage by an additional 5%.
- Grants you Minor Resolve while transformed.
- Shadow of the Bloodmoon
- Reduces the cost of Werewolf abilities while you are a Pack Leader by 33%.
- Call of the Hunt
- Reduces the cost of Werewolf Transformation by an additional 20% for you and your group members.
Other ideas include "Gain a stack of Blood Hunger", "Consume a stack of Blood Hunger to increase the efficiency of the Focus Script by 25%", and "While you are in Rampage, gain x effect", which relate more to the active abilities than they do the passive abilities.
And that's all 20 Signature Scripts! Some of these are more fitting for a Werewolf Grimoire than others, and some of them would apply very useful effects that are absent from the Werewolf skill line currently. As always, remember that we would be giving up 1 of our 5 Werewolf abilities for this 1 crafted Werewolf ability, so whatever it is should thematically and functionally mesh well with the other skills in the Werewolf toolkit. I really hope we get a Werewolf Grimoire some day!
@ZOS_Kevin @ZOS_JessicaFolsom