Nikke in the Mirror Guide: Dominate the Mirror Boss Fight

Basic Information about Mirror

• Element: Water
• Weakness: Electric
• Strong Against: Fire
• Rewards: Gloves, Custom Modules
• Total HP: 5,800,000

Understanding the basic attributes of Mirror is crucial for effective team building and strategy. As a Water element Nikke boss, Mirror is vulnerable to Electric attacks. Capitalizing on this weakness will significantly increase your damage output and clear speed. Conversely, using Fire element Nikkes will be less effective due to elemental resistance. The rewards for defeating Mirror include Gloves and Custom Modules, valuable resources for enhancing your Nikkes. The total HP of 5.8 million indicates a moderately challenging boss fight, requiring a well-prepared team and understanding of its mechanics.

Stages and Rewards Breakdown

Progressing through the stages of the Mirror boss fight yields increasingly valuable rewards. The table below outlines the damage thresholds for each stage and the corresponding percentage chance of obtaining Arm Boxes and Custom Modules.

As you can see, reaching higher stages significantly increases your chances of obtaining better rewards. Aiming for Stage 9, which requires dealing 5.8 million damage, maximizes your reward potential. This stage offers the highest drop rates for both Arm Boxes and Custom Modules, making it the most efficient stage to farm for resources.

Mirror’s Abilities: How to Counter Each Attack

Understanding Mirror’s abilities is key to surviving and thriving in this boss fight. Each ability has its own mechanics and counters, which we will detail below.

Crystal Missile

Launches small crystals at a single Nikke, dealing damage. Crystals can be intercepted.

Crystal Missile is a straightforward attack where Mirror launches a volley of projectiles at a single Nikke. These projectiles are launched from both sides of the boss simultaneously and can be intercepted. Nikkes with high interception capabilities or well-timed burst skills can negate this attack, minimizing damage taken.

Replica Glass Slippers Normal Attack

Summons Replica Glass Slippers and fires lasers at the Nikke with the highest ATK. Replica Glass Slippers can be destroyed with just one attack.

This ability summons Replica Glass Slippers on either the left or right side of Mirror. These slippers target the Nikke with the highest ATK and fire lasers. The crucial aspect is that these summons can be destroyed with a single, powerful attack. Failing to destroy them in time will result in taking laser damage.

Units equipped with Sniper Rifles or Rocket Launchers, especially those with full charge mechanics like Ein, Red Hood, Alice, or Exia, are highly effective at one-shotting these slippers. Scarlet, with her significant ATK buffs, can also handle this mechanic efficiently.

Rapid-Fire Rifle

Continuously attacks the Nikke with the highest ATK with a machine gun.

Rapid-Fire Rifle is a simple, continuous machine gun attack targeting the Nikke with the highest ATK. There are no special mechanics to this ability, and it primarily serves as consistent damage pressure throughout the fight. Healers or Nikkes with high defense can mitigate the impact of this attack.

Replica Glass Slippers Full Attack

Summons all Replica Glass Slippers, dealing damage to all Nikkes. Generates a defensive barrier when using Replica Glass Slippers Full Attack. While the barrier is up, only Electric Code Nikkes can deal damage.

This is an Elemental Quick-Time-Event (QTE). Mirror summons multiple Replica Glass Slippers, dealing damage to the entire team and deploying an elemental barrier. During this barrier, only Electric Code Nikkes can effectively damage Mirror.

Successfully breaking the two circles that appear during this QTE requires a team composition that includes strong Electric Nikkes. Failing to break the barrier quickly will prolong the fight and reduce your damage output.

Harmony Cube Overload

Emits shockwave forward from the Harmony Cube. Can only be stopped through Special Interruption. Should an attempt at Special Interruption fail, the shockwave deals damage to all Nikkes.

Harmony Cube Overload is a Normal Quick-Time-Event (QTE). Mirror goes off-screen and summons four circles sequentially that need to be interrupted. Importantly, gray circles also appear and destroying these will result in a failed QTE, leading to a shockwave that damages all Nikkes. Focus on interrupting only the correct, non-gray circles to successfully counter this ability.

Glass Slippers Attack Mode

Summons Glass Slippers at a single Nikke, dealing damage. Glass Slippers can be destroyed with just one attack.

Glass Slippers Attack Mode is another tricky mechanic. Slippers extend from one of the four corners of Mirror and target a single Nikke. In Attack Mode, these slippers must be destroyed with a single shot to reduce Mirror’s defense. Failure to destroy them quickly will result in them becoming invulnerable and buffing Mirror’s defenses, making the fight harder.

Similar to the Replica Glass Slippers, Sniper Rifles and Rocket Launchers are ideal for one-shotting these slippers. Pause tech, as explained later, can be particularly useful for consistently destroying these slippers.

Glass Slippers Destroy Mode

Summons all Glass Slippers, dealing damage to all Nikkes. Generates a defensive barrier when using Glass Slippers Destroy Mode. While the barrier is up, only Electric Code Nikkes can deal damage.

This is another Elemental Quick-Time-Event (QTE), similar to Replica Glass Slippers Full Attack. Mirror spins and summons four circles that can only be broken by Electric Code Nikkes. Having a team ready with strong Electric Nikkes is crucial to quickly handle this phase and continue dealing damage.

Harmony Cube Laser

Continuously fires lasers at the Nikke with the highest ATK from the Harmony Cube.

Harmony Cube Laser is a continuous laser attack directed at the Nikke with the highest ATK. This ability is straightforward and adds to the sustained damage output of Mirror. Nikkes with high survivability or healing support can withstand this attack.

Crystal Arrow

Launches Crystal Needles at multiple Nikkes, dealing damage. Crystal Needles can be intercepted.

Crystal Arrow is similar to Crystal Missile but launches larger projectiles at multiple Nikkes. These projectiles can also be intercepted. Prioritize interception to minimize team-wide damage.

Glass Slippers Defense Mode

Summons Glass Slippers and drastically increases Mirror Container’s defense. While Glass Slippers are in attack mode, they can be destroyed with just one attack. Destroying them can decrease Mirror Container’s defense.

In Defense Mode, the Glass Slippers significantly buff Mirror’s defense. Crucially, while in attack mode (which is likely a typo in the original description and should refer to when slippers are vulnerable), destroying these slippers will decrease Mirror’s defense. This highlights the importance of recognizing the slipper modes and prioritizing their destruction when they are vulnerable to reduce Mirror’s overall defense.

General Tips for the Mirror Boss Fight

• Utilize Sniper Rifles and Rocket Launchers for Burst Generation: Quickly firing Sniper Rifles (SR) or Rocket Launchers (RL) without full charging is an effective way to generate burst skill quickly. This is especially useful for SR/RL Nikkes without full charge mechanics.

• One-Shot Slippers: Both Replica Glass Slippers (Phase 1) and Glass Slippers (Phase 2) require being destroyed with a single, powerful shot. Failing to do so will lead to negative consequences, such as invulnerability or defense buffs for Mirror.

• Pause Tech for Slippers: A useful technique for consistently destroying slippers is “pause tech.” Pause the game when slippers appear, move your cursor to the slipper while charging a Sniper Rifle or Rocket Launcher, and release the trigger upon unpausing. This ensures precise targeting and destruction of the slippers.

Recommended Teams to Defeat Mirror

Here are some team compositions that are effective against Mirror, categorized by best teams and incomplete box teams.

Best Teams for Mirror

These team compositions are highly optimized for the Mirror boss fight, leveraging strong Nikkes and elemental advantages.

• Cinderella, Rouge, Ein, Crown, Anis: Sparkling Summer
• Crown, Naga, Cinderella, Rouge, Anis: Sparkling Summer
• Crown, Naga, Ein, Rouge, Anis: Sparkling Summer
• Crown, Naga, Cinderella, Rouge, Ein
• Cinderella, Rouge, Anis: Sparkling Summer, Crown, Maiden: Ice Rose
  • Note: Exia with treasure can be substituted for Naga.

These teams prioritize Electric Nikkes (like Ein and Crown) to exploit Mirror’s weakness and often include strong burst generators and damage dealers like Cinderella and Rouge.

Incomplete Box Team Options

If you don’t have access to the “best teams,” these are viable alternatives using more commonly available Nikkes. It’s recommended to include at least one healer or taunter for survivability in these compositions.

• Usable Burst 1 Nikkes: Rapi: Red Hood, Rouge, Liter, D: Killer Wife, Volume, Dorothy.
• Team Examples:
  • Crown, Flex B1, Red Hood, Alice, Naga
  • Tia, Flex B1, Naga, Flex B3, Flex B3
  • Flex B1, Blanc, Scarlet, Noir, Flex Attacker
  • Tove, Leona, Privaty: Unkind Maid, Soda: Twinkling Bunny, Alice: Wonderland Bunny

These teams offer flexibility and allow you to adapt based on your Nikke roster. Experiment with different Burst 1 Nikkes and damage dealers to find the best combination for your account. Remember to prioritize Electric damage dealers and consider including Nikkes that can intercept or heal to enhance your survivability against Mirror’s attacks.