As you may have realised, some of the skills in Octopath Traveler 2 don't do what they say they do. I've gone through all the combat and support skills in both English and Japanese and compiled a list of the most egregious offenders.

While I would personally rewrite most of the skills to be clearer and more faithful to the Japanese descriptions, I will try my best to limit this list to only mistranslations and extremely vague/misleading descriptions. Fixes will endeavour to be as close to the EN localisation's style and terminology as possible.

This is not an exhaustive list. If you've discovered anything else that seems mistranslated, leave a comment and I'll add it to the list.

This is a quick list of the skills with fixed descriptions (and occasionally titles). I'll denote the completely mistranslated ones with > (as opposed to the vague/misleading ones).

If you want to see what was changed or why it was changed (with pictures), head to the Detailed Explanations sections.

> (Support Skill) Heighten Senses: "The party has an increased chance of attacking with initiative. (Equipping multiple characters with this skill will have no added effect.)"

• Alternative description: "The party has an increased chance to gain an extra turn at the start of battle, during which enemies are unable to act. (Equipping multiple characters with this skill will have no added effect.)"

(EX Skill) Remedy: "Grant random allies positive effects 3 times."

> (EX Skill) Veil of Darkness: "Deal dark-based damage to all foes, and make them miss their next physical attack with a 100% success rate."
> (EX Skill) Disguise: "Disguise yourself as a single ally for 2 turns."

> (Support Skill) Advanced Magic Master: "When the equipping character boosts the intensity of a character's spells, they grant an additional instance of the buff."

> (EX Skill) Share SP: "Grant all allies 25% of your remaining SP."
(EX Skill) Negotiate Schedule: "Pay a single foe to let you act during one of their actions."

> (EX Skill) Song of Hope: "Extend the duration of all allies' positive effects by 1 turn. This does not affect divine skills."

> (EX Skill) Prayer for Plenty: "Restore HP to a single ally, granting them HP beyond the maximum if they are at or below max HP."
> (Support Skill) Resilience: "Raises the amount of HP restored by the equipping character's healing skills."

> (Combat Skill) Enervating Slash: "Nullify all positive effects on yourself, then unleash a sword attack. The more effects you nullify, the more potent the attack."
> (Learned Skill) Divine Protection: "Grant a single ally 1 instance of invincibility."
> (Learned Skill) Purgatory: "Deal heavy fire-based damage to all foes." <Credit to marcv666 for this one.>

(Combat Skill) Elemental Bomb Bottle: "Deal the same type of damage as a single foe’s exposed elemental weak points 1 time per weakness."
(Support Skill) A Step Ahead: "The equipping character will act with initiative."

• Alternative description: "The equipping character gains an extra turn at the start of battle, during which enemies are unable to act."

(Combat Skill) Dancer’s Blade: Mischievous Step Dance

• This is a Dance for the purposes of Agnea's Talent.

> (Support Skill) Arms Refinement: "Fills the equipping character’s latent power gauge when exploiting an enemy’s weak point with a weapon."

(Divine Skill) BP Boost: "Increases a single ally’s passive BP regeneration to 2 BP per turn for 3 turns."

Herb of Revival Consciousness (Cures a single ally of unconsciousness)
> Ancient Sentinel Core (Raises the elemental attack and elemental defense of a single ally for 2 turns.) <Credit to marcv666 for this one.>

• Everything below in bullet points includes my rationale, alternate translations, and additional information. Literal translations will be provided if I feel they add needed context.
  
• I have included pictures with big red circles and big red arrows for most skills.
  
• [Formatting] (Type of Skill) Skill Name: "Original EN localisation. My revisions."

(Support Skill) Heighten Senses: "Gain The party has an increased chance of attacking first in combat with initiative. (Equipping multiple characters with this skill will have no added effect.)"

• Initiative: "Gain an extra turn at the start of battle, during which enemies are unable to act."
  
• The term 'initiative' is used by the EN localisation for the the "Provoke Like a Pro" bonus, which states, "You will always gain initiative when you Provoke the residents of this town!"
  
• I personally would rename 'initiative' to 'Preemptive Strike', since it's closer to the JP text and more clearly describes the mechanic.
  
• Literal translation: "Preemptive attack's chance increases *With multiple people, effect does not stack".
  
• Alternative description: "The party has an increased chance to gain an extra turn at the start of battle, during which enemies are unable to act. (Equipping multiple characters with this skill will have no added effect.)"

(EX Skill) Remedy: "Grant a random ally 3 positive status effects Grant random allies positive effects 3 times."

• This skill at no boost involves Castti taking 3 buffs and applying them to allies at random. It can hit the same ally more than once, as shown in the second image above.
  
• The original EN translation states that Castti will give a random singular ally 3 buffs—this is incorrect, especially compared to the wording of skills like Scholar's Elemental Barrage (re: plurality of targets).
  
• It also states that she will only give positive status effects—this is also incorrect. The skill includes what seems to be most (if not all) positive effects, from 1 turn of physical attack up (i.e. an "attribute-raising effect", AKA a stat buff) to multiple turns of Sealtigce’s Seduction (i.e. a "positive status effect").

(EX Skill) Veil of Darkness: "Deal dark-based damage to all foes, and dodge 1 physical attack make them miss their next physical attack with a 100% success rate."

• Literal translation: "Deal dark elemental damage to all enemies, and grant them 1 instance of an effect causing them to be guaranteed to miss a physical attack."

(EX Skill) Disguise: "Disguise yourself as a single ally for 2 turns."

(Support Skill) Advanced Magic Master: "Raises the number of times the equipping character can use more intense spells by 1 When the equipping character boosts the intensity of a character's spells, they grant an additional instance of the buff."

• Alternative translations for this mechanic, borrowing from Pokémon terminology:
  
• (Combat Skill) Advanced Magic: "Grant a single ally 2 instances of the 'Great Magic' buff."
  
• (Divine Skill) Alephan's Wisdom: "Grant a single ally 3 instances of the 'Ultra Magic' buff."
  
• (Support Skill) Advanced Magic Master: "When the equipping character grants instances of 'Great Magic' or 'Ultra Magic', they grant an additional instance."
  
• A literal translation isn't possible without sounding wonky. Here's a fairly literal translation of Advanced Magic: "Grant a single ally 2 instances of the effect of used 'Magic' being 'Turned Big'."

(EX Skill) Share SP: "Grant a single ally all allies 25% of your remaining SP."
(EX Skill) Negotiate Schedule: "Pay a single foe to let you act during their turn one of their actions."

• Literal translation: "Pay money and change one of a single enemy's action turns to your own action turn."

(EX Skill) Song of Hope: "Extend the duration of a single ally's all allies' positive status effects by 1 turn. This does not affect divine skills."

(EX Skill) Prayer for Plenty: "Restore HP to a single ally, ignoring their max HP granting them HP beyond the maximum if they are at or below max HP."

• "ignoring their max HP" is extremely vague and fails to address the fact that this skill only works when the target is at or below max HP.
  
• Considering Armsmaster's Peak Performance is capable of describing "at or above max HP", it's weird how they didn't think it was important to include the 最大ＨＰ以下のとき (when at or below max HP) part of this skill.

(Support Skill) Resilience: "Raises the amount of HP restored to by the equipping character when healed character's healing skills."

• Literal translation: "The equipping person's HP healing skills' healing amount increases."

(Combat Skill) Enervating Slash: "Nullify all positive status effects on a single foe yourself, then unleash a sword attack. The more status effects you nullify, the more potent the attack."

• 'Enervating' only works in the mistranslation. There’s no real good way to translate the 無心 part of 無心の太刀 in a single word, but 'Blade of Clear Mind' and 'Zen Blade' are options.

(Learned Skill) Divine Protection: "Grant a single ally 1 turn instance of invincibility."

• The NPC for this is at the podium in Canalbrine's church.
  
• Literal translation: "To a single ally, grant 1 instance of an effect that makes you not receive every attack."

(Learned Skill) Purgatory: "Deal heavy fire-based damage to all foes 3 times."

• This can be acquired from a Sanctum Knight a little to the northeast of Stormhail's entrance during daytime.
  
• Credit to marcv666 for this one.

(Combat Skill) Elemental Bomb Bottle: "Deal the same type of damage as a single foe’s exposed elemental weak points 1 time per weakness."



(Support Skill) A Step Ahead: "The equipping character will act first at the start of battle with initiative."

• Initiative: Gain an extra turn at the start of battle, during which enemies are unable to act.
  
• Important: Even if only one character has this skill, BP regeneration still activates on the next turn of battle, effectively making it like you have Merchant's Boost Start on all your characters for free.
  
• Literal translation: "Only the equipping person will act at the beginning at battle start."
  
• Alternative description: "The equipping character gains an extra turn at the start of battle, during which enemies are unable to act."

• "Weapon Master" in Japanese.
  
  

(Combat Skill) Dancer’s Blade: Mischievous Step Dance

• This clarification is relevant for Agnea's Talent.
  
• You can argue that "Step" used in this context is clearly a dance, but the original text made it explicit that Agnea's「舞」系のアビリティ([Dance]-type Abilities) trigger effects from people she's Allured. You can see how 舞 is in Japan's version of quotation marks, which is a clear attempt at being unambiguous about which abilities are affected.

(Support Skill) Arms Refinement: "Fills the equipping character’s latent power gauge when exploiting an enemy’s weak point with a weapon."

• Elemental damage doesn’t count. Yes, "with a weapon" was clarified in the original JP text.

• "Black Magician" or "Heretic" in Japanese.

• "Exorcist" in Japanese.

(Divine Skill) BP Boost: "[Divine Skill] Grant a single ally 2 BP at the start of every turn for 3 turns Increases a single ally’s passive BP regeneration to 2 BP per turn for 3 turns."

• The original EN localisation suggests you get an extra 2 BP per turn.
  
• I localised this skill to what it actually does (i.e. You still regenerate 0 BP the turn after you use BP).
  
• Literal translation: “Secret technique. To a single ally, grant an effect that increases BP per turn to 2 for 3 turns.”

Herb of Revival Consciousness (Revives a single unconscious ally Cures a single ally of unconsciousness.)

• Very vague. "Revive" is generally reserved for bringing back characters who have gone to 0 HP.
  
• 気絶 is usually translated as “Stunned” in these types of games. Along with, you know, the swirling stars above their heads.

Ancient Sentinel Core (Raises the elemental attack and physical elemental defense of a single ally for 2 turns.)

• Credit to marcv666 for this one.

Hopefully, this saves some of you the frustration of trying to figure out which skills were mistranslated.

Of the 84 combat skills, 12 Divine Skills, 16 EX Skills, and 48 Support Skills, these are the ones that stood out most to me. If you feel there are any other skills among the aforementioned that should be added to the list—or if there are items, equipment, monster skills, or learned skills you believe are mistranslated—leave a comment. I'll check it out and add it to the list if it's mistranslated or overly ambiguous.