Giving the Merc Whistle to an ally will get you a unique Special Accessory available once per run. Learn about each reward you can get for a Merc Whistle and the best character to give the Merc Whistle to!

Who to Give the Merc Whistle To

Best Given to Byleth

Byleth's Divine Pulse is arguably the best Action Ability in the game, as it freezes time for all surrounding enemies, including commanders, for as long as 20 seconds, allowing you and your party to simply pummel them with no resistance.

Max Out Support Before Chapter 15

Byleth is obtained late in the game, making it tricky to raise your Support Level with them to A, but it's worth it to be able to give their powerful Action Ability to another character.

Be sure to raise your Support Level to A and watch the Support Conversations with Byleth before Chapter 15. After this point, you won't be able to watch Support Conversations anymore, making it impossible to obtain Byleth's Special Accessory without trying again on another playthrough.

How to Recruit Byleth

List of Merc Whistle Rewards

Character	Special Gift	Unique Ability
Byleth	Tactics Primer	Divine Pulse Press ZR to stop time. A follow-up attack will trigger when time restarts, based on damage dealt during the stoppage. Has a short cooldown time.
Edelgard	Imperial Coat of Arms Pen	Solar Prominence Imbue attacks with fire.
Dimitri	Azure Dagger	Azure Lightning Imbue attacks with lightning.
Claude	Notes on Poisons	Dustcloud Imbue attacks with wind.
Mercedes	Rose Water	Radiant Love Attacking very slightly fills the Unique Ability Gauge and gradually restores HP. When the gauge is full, press ZR to damage enemies and heal allies.
Annette	Wooden Doll	Courageous Aria Attacking very slightly fills the Unique Ability Gauge. When it is full, press ZR to temporarily strengthen yourself and surrounding allies.
Sylvain	Warm Cloak	Gordian Stroke At 300 hits and above: increase attack range and damage dealt proportional to hit count.
Ingrid	Pegasus Hair Charm	Icy Plunge Enemies sent flying explode and deal ice damage to a narrow area.
Seteth	Simple Fishing Rod	Windswept Imbue non-regular attacks with wind. Press ZR to rend Windtorn enemies with air blades. Has a long cooldown time.
Flayn	Sand from Rhodos Coast	Luminous Prayer Gain a chance to spawn 2 orbs of light around the unit when performing regular attacks. Press ZR to fire a beam of light toward all orbs.
Yuri	Silver Ring	Deceit Press ZR to create an orb of wind that draws in enemies and explodes. Has a long cooldown time.
Shamir	Animal Bone Dice	Cold Calculation Strike with the right timing to slightly increase critical hot rate andd imbue attacks with ice.
Bernadetta	Shez Doll	Personal Space Press ZR to create a zone of ice that increases critical hit rate. Has a long cooldown time.
Linhardt	Portable Lamp	Easy Breezy Complete a final regular attack to spawn a pair of wind orbs in front of the unit. The orbs automatically attack in a narrow range.
Petra	Knife and Scabbard	Windstorm Slightly increase evasion distance. Dodges inflict very minor wind damage.
Felix	Wooden Training Sword	Intense Velocity Dodge in the middle of an attack to increase speed by one tier for a period of time. Will reach maximum speed after 7 dodges.
Hilda	Bottle of Flowers	Lightning Bound Hold the button during strong attacks to slightly increase damage and add lightning. While charging, enemies a short distance away will be drawn in.
Lorenz	Rose Brooch	Rondo of Roses Attacking fills the Unique Ability Gauge, while nullifying an enemy attack decreases it. When the gauge is full, press ZR to draw in foes a short distance away.
Raphael	Wooden Dish	Pure Brawn Charge to power up attacks for a set period. Attacks will strengthen up to 2 tiers based on the number of charges.
Ignatz	Travelogue	Dreamer's Paintbrush Send enemies flying to splatter the ground with a small amount of paint. Enemies that step in the paint incur elemental damage matching its color.
Lysithea	Amber Sweetener	Cursed Expulsion Enemies sent flying explode and deal dark damage to a narrow area. Press ZR to draw in Spellbound enemies. Can be used again after a cooldown.
Marianne	Fancy Handkerchief	Snowslip At 300 hits and above: spawn falling ice orbs that deal ice damage to foes at intervals proportinal to hit count.
Constance	Curse-Repelling Amulet	Personality Shift Generate a small number of orbs with each attack. The orbs will be light or dark depending on the stage, up to a total of 6. Press ZR to launch the orbs.
Balthus	Secret Medicine	Golden Fists At 300 hits and above: power up attacks proportional to the hit count. Sending enemies flying grants a very small amount of gold.
Hapi	Amethyst Charm	Nether Sigh Strong attacks and the unit's final regular attack generate small zones in front of the unit that deal dark damage. Press ZR to detonate the zones and cause a small explosion.
Holst	Mushroom Powder	Galvanic Surge Attacking slightly fills the Unique Ability Gauge. When it is full press ZR to temporarily increase speed and imbue attacks with lightning.
Jeralt	Beast Repellent	Blade Breaker Hold the button when performing storng attacks to slightly increases damage, guard break, and explode enemies sent flying.
Catherine	Dagdan Whetstone	Twofold Ruin Press ZR to make attacks hit twice for a period of time and deal a small amount of additional damage. This skill can be reused periodically.
Dedue	Metal Clasp	Demolisher Hold the button when performing strong attacks to trigger blasts on impact that deal minor damage to enemies.
Leonie	Hunter's Knife	Careful Study Allows the unit to string together 2 times the normal number of regular attacks. Based on the number of consecutive hits, speed will increase, and final regular or strong attacks will strengthen.
Jeritza	Odd Charm	Quietus Attacking very slightly fills the Unique Ability Gauge and increases damage dealt to enemies. When the gauge is full, press ZR to attack, instantly defeating non-commander enemies.
Dorothea	Silver Bracelet	Prismatic Resonance Gain a low chance to spawn musical notes around the unit when performing regular attacks. Attacking the notes triggers elemental shockwaves.
Hubert	Sharp Dagger	Dark Conjuration Gain a low chance to impale an attacked enemy with a magic spike. Additional attacks power up the spike. Press ZR to detonate the spike and inflict dark damage based on power level.
Ferdinand	Weapon Repair Oil	Maximum Ambulation At 300 hits and above: gain an increase in speed proportional to hit count.
Caspar	Seasoning Set	One for the Books Hold the button when performing strong attacks to charge the attack, increasing attack range and damage dealt by one tier.
Manuela	First Aid Kid	Thunderous Refain Attacking generates lightning-imbued musical staves and fills the Unique Ability Gauge. When the gauge is full, press ZR to deal a small amount of damage around the staves.
Monica	Portable Tea Set	Wicked Impulse Strike with the right timing to generate a small shockwave imbued with an element corresponding to the attack.
Rodrigue (Recruit Byleth)	Drinking Horn	Martial Prowess Strike with the right timing to slightly increase damage, attack range, and knockback rate.

The Merc Whistle cannot be given to characters recruited using Renown.

How to Recruit All Playable Characters

What is the Merc Whistle?

Gives You a Character's Action Ability

At the start of Chapter 10, Shez will receive the Merc Whistle, a special item that only allies with an A Support Level with Shez can receive.

You will only receive one per playthrough, so it's best to give it to a character who will give the best abilities!

Story Walkthrough: List of Chapters

A Very Special Friend Achievement

When Shez has given a character their Merc Whistle, you will receive an Achievement called A Very Special Friend, which serves as proof that you've received a special gift from one of your allies.

List of All Achievements and Awards

Fire Emblem Warriors: Three Hopes Related Guides

Tips and Tricks

All Tips and Tricks