In Fire Emblem Warriors, weapons can have one or more attributes that provide additional effects beyond the weapon's base damage. The number of attributes that a weapon may have varies by the individual weapon.

Attributes affect a variety of parameters, such as increasing the weapon's base damage, boosting the wielder's attack speed, swapping the unit's Strength and Magic values, or imparting the ability to deal effective damage against specific enemy types, including categories of enemies that are not traditionally subject to effective damage in mainline Fire Emblem titles.

Name	Effect	Type	KO Count	Weapon Required to Unlock	Notes
Strong I	Increases Strong Attack I damage (X)	Attack	N/A	N/A	Raises boosted attack's damage by 25%
Strong II	Increases Strong Attack II damage (Y, X)	Attack	N/A	N/A	Raises boosted attack's damage by 25%
Strong III	Increases Strong Attack III damage (Y, Y, X)	Attack	N/A	N/A	Raises boosted attack's damage by 25%
Strong IV	Increases Strong Attack IV damage (Y, Y, Y, X)	Attack	N/A	N/A	Raises boosted attack's damage by 25%
Strong V	Increases Strong Attack V damage (Y, Y, Y, Y, X)	Attack	N/A	N/A	Raises boosted attack's damage by 25%
Strong VI	Increases Strong Attack VI damage (Y, Y, Y, Y, Y, X)	Attack	N/A	N/A	Raises boosted attack's damage by 25%
Rainstorm	Increases all Regular Attack damage (Y)	Attack	N/A	N/A	Raises normal attacks' damage by 25%
Power Up	Weapon drops will have more slots	Drop	N/A	N/A
First Class	Weapon drops are of higher quality	Drop	N/A	N/A
Healer	Increases drop chance of recovery items	Drop	N/A	N/A
Topsy-Turvy	Swaps physical and magical attack power	Swap	N/A	Conduit Sword Conduit Lance Conduit Axe Conduit Bow Conduit Tome	Works like Magic Weapons in other games (E.G. A bow with Topsy-Turvy will target Res instead of Def)
Antitriangle	Reverses weapon-triangle effects	Swap	N/A	Lancereaver Axereaver Swordreaver
Statflip	Swaps both Atk & Def and Mag & Res	Swap	N/A	Statflip Sword Statflip Lance Statflip Axe Statflip Bow Statflip Tome Statflipstone	Also affects Resonating Power
Mountslayer	Bonus vs. Mounted Units	Bonus	N/A	Zanbato Horseslayer Poleax Hunter's Bow Unsaddler Tome Piked Dragonstone	-20% Mt for a weapon that does not have an Awake attribute
Wingslayer	Bonus vs. Flying Units	Bonus	N/A	Wing Clipper Flycatcher Volant Axe Wingbane Tome Risestone	-20% Mt for a weapon that does not have an Awake attribute (Excluding Bows)
Plateslayer	Bonus vs. Armored Units	Bonus	N/A	Armorslayer Heavy Spear Hammer Cleave Bow Piercing Tome Ironbanestone	-20% Mt for a weapon that does not have an Awake attribute
Dracoslayer	Bonus vs. Dragon Units	Bonus	N/A	Wyrmslayer Dragonpike Dragon Axe Dragonkiller Bow Condragon Tome Undragonstone	-20% Mt for a weapon that does not have an Awake attribute (Excluding The Falchion, Parallel Falchion, Exalted Falchion, Sol Katti, and The Divinestone even before unlocking True Power or Divine Blessing)
Beastslayer	Bonus vs. Monster Units	Bonus	N/A	Spirit Katana Blessed Lance Blessed Axe Blessed Bow Blessed Tome Blessedstone	-20% Mt for a weapon that does not have an Awake attribute (Excluding Facinna and Enliron even before unlocking True Power or Divine Blessing)
Rampager	Bonus vs. Mounted and Armored Units	Bonus	N/A	Only available to the Wing Spear
Healing Gift	Full HP after every 300 kills	Defeat	2000	N/A
Warrior Gift	Full Warrior Gauge after every 300 kills	Defeat	2000	N/A
Awakening Gift	Full Awakening after every 300 kills	Defeat	2000	N/A
Fury Builder	Increases damage per 100 foes defeated	Fury	2500	N/A	Raises damage dealt by 5% for every 100 KOs for the rest of the battle; limited only to the character who has the attribute, does not include KOs gotten by CPU controlled characters
Armor Strike	Shatters armor with powerful attacks	Break	3000	Armorbane Sword Armorbane Lance Armorbane Axe Armorbane Bow Armorbane Tome Armorbanestone	Halves enemy Def/Res when landing a critical strike, does not stack with Luna; Halves own Def/Res for the rest of the battle when hit with a strong attack. Required to break the armor of/have your armor broken as a character to unlock their broken armor model in the model viewer
Critical Focus	Attacks deplete the Weak Point Gauge faster	Focus	4000	N/A
Anti-Air Focus	Increases damage versus launched foes	Focus	4000	N/A	Increases damage to launched enemies by 25%
Triangle+	Increases weapon-triangle advantages	Boost	5000	N/A	Boosts damage when attacking an enemy with weapon triangle disadvantage by 25%; affects all weapons when in Awakening Mode
Pair Up+	Increases damage when paired up	Boost	5000	N/A	Increases damage by 25% while paired up
Critical+	Increases Critical Hit damage	Boost	5000	N/A	Increases the power of Critical Hits and Critical Rushes by 25%
Warrior+	Increases special attack damage	Boost	5000	N/A	Boosts the damage of Warrior Specials by 25%
Health+	Increases damage when at max HP	Boost	5000	N/A	Boost damage by 25% when at max HP
Desperate+	Increases damage when at low HP	Boost	5000	N/A	Slowly increases damage dealt the less HP you have, capping at +25% when you have 1% HP
Swordbreaker	Increased damage vs. sword wielders	Slay	N/A	Swordbane Sword Swordbane Lance Swordbane Axe Swordbane Bow Swordbane Tome Swordbanestone
Lancebreaker	Increased damage vs. lance wielders	Slay	N/A	Lancebane Sword Lancebane Lance Lancebane Axe Lancebane Bow Lancebane Tome Lancebanestone
Axebreaker	Increased damage vs. axe wielders	Slay	N/A	Axebane Sword Axebane Lance Axebane Axe Axebane Bow Axebane Tome Axebanestone
Bowbreaker	Increased damage vs. bow wielders	Slay	N/A	Bowbane Sword Bowbane Lance Bowbane Axe Bowbane Bow Bowbane Tome Bowbanestone
Tomebreaker	Increased damage vs. tome wielders	Slay	N/A	Tomebane Sword Tomebane Lance Tomebane Axe Tomebane Bow Tomebane Tome Tomebanestone
Stonebreaker	Increased damage vs. stone wielders	Slay	N/A	Dragonbane Sword Dragonbane Lance Dragonbane Axe Dragonbane Bow Dragonbane Tome Dragonbanestone
Clawbreaker	Increased damage vs. claw wielders	Slay	N/A	Clawbane Sword Clawbane Lance Clawbane Axe Clawbane Bow Clawbane Tome Clawbanestone
Gencross	Bonus vs. other gender; weaker vs. same	Gen	N/A	Gencross Sword Gencross Lance Gencross Axe Gencross Bow Gencross Tome Gencrossstone	+50% Damage versus the opposite gender, -15% damage versus the same
Genpeer	Bonus vs. Same gender; weaker vs. other	Gen	N/A	Genpeer Sword Genpeer Lance Genpeer Axe Genpeer Bow Genpeer Tome Genpeerstone	+50% damage versus the same gender, -15% damage versus the opposite
Amped	Boosts all stats except Mov. (20%)	Spirit	N/A	Amped Sword Amped Lance Amped Axe Amped Bow Amped Tome Ampedstone
Bolster	Strengthens Attack and Boost attributes	Spirit	N/A	Bolster Sword Bolster Lance Bolster Axe Bolster Bow Bolster Tome Bolsterstone	Doubles the effect of all Attack and Boost skills (I.E., 25% becomes 50%)
Acceleration	Increases attack speed	Spirit	N/A	Acceleration Sword Acceleration Lance Acceleration Axe Acceleration Bow Acceleration Tome Accelerationstone	Boosts attack speed by 50%, does not stack with Astra or Strike Rate+
True Power	Increases stats of exclusive weapons (240)	Awake	10,000	Unique weapons only. Requires Mastery Crest.
Divine Favor	A divine blessing that improves a weapon (720)	Awake	N/A	Unique weapons only. Requires Sanctuary Crest. Replaces True Power.
Legendary	Increases a weapon's basic stats	Awake	6000	Legendary Sword Legendary Lance Legendary Axe Legendary Bow Legendary Tome Legendarystone	Raises a weapon's Mt to 480 and prevents it from being lowers by Bonus attributes
Strike Rate+	Increases attack speed	Awake	N/A	Chrom's Training Sword only	Raises Attack Speed by 60%, does not stack with Astra or Acceleration
All Stats+	Increases all stats except Mov	Awake	N/A	Tiki's Tear only	Raises all stats except Mov by 5 and HP by 50

Credit to Tables on the Serenes Forest wiki for testing and compiling a lot of information in the notes section.

Subjective: The following part of this article is based upon the editor's personal experiences and opinions, and therefore may not be applicable for all readers.

The general best weapon builds are the same universally for all characters in Fire Emblem Warriors, but you can change small aspects if you have preference for a certain playstyle or want to try different builds with certain skills. But in general you want to get Critical Rush, one boost skill (most agree on Critical+ or Pair Up+ due to their consistency), if you have a PRF weapon then Swordbreaker due to the abnormally high amount of sword enemies (or axebreaker for lancer) and a bonus category attribute that covers the weakness of said weapon (E.G. putting Swordbreaker on Olivia's Blade as well as Wingslayer to then deal with high Def lance wielding cavaliers), and either Amped or Bolster depending on the Luck stat of your character (Generally, you would only give Bolster to incredibly low luck characters like Frederick.) This is because Amped boosts all stats by 20%, including Luck which is used for what are arguably the two strongest skills in the game: Luna and Lethality, as well as gold grinding skills like Payday. It also boosts all other stats which gives general utility too like longer Awakening Modes and better tanking. Whatever remaining slots are on the weapon are all up to preference.

Notes

• All of the bonuses provided are additive, not multiplicative. Meaning if you have two attributes which boost by 25%, you will get a 50% boost, not a 56.25% boost. There are a few exceptions to this, like Luna which is why is is regarded to be as powerful as it.
• Like with other Fire Emblem games, Weapon MT and Attack stats (Str/Mag or Def/Res with Statflip) are added together. However, due to Brave and Hero weapons, as well as PRF weapons with True Power/Divine Favor having far more MT than any max level character's attack stats, attack stats effectively become irrelevant once you unlock later game weapons.
• Attributes are put into different categories (ie. Attack, Bonus, etc.), and every weapon can have a max amount of each category of attribute: Attack - 6, Drop - 4, Swap - 2, Bonus - 2, Defeat - 1, Fury - 1, Break - 1, Focus - 1, Gen - 1, Boost - 1, Awake - 1