Many sync pairs need to gain access to their full grid to become useful. Serena & Delphox are the exception—their sync grid only makes them more powerful.

The best sync grid build for Serena & Delphox would be to go for a balanced refresh build, a Fire Spin-focused build, or an Overheat build.

Sync Grid Builds

The All-Around Refresh build is immediately available at sync level 1 and picks up all tiles capable of restoring bars on the move gauge. 

At sync level 2, the Trapped Fire Spin build works on damaging opponents with the trapped condition to help your main striker. 

The Impervious Overheat build positions Delphox as a powerhouse against helpless opponents when this sync pair gains access to their full grid at sync level 3.

All-Around Refresh Sync Build (Sync Level 1/5)

(build link)

Total Sync Orb Cost: 750
Total Energy Used: 60
Total Upgrades:

• HP +20
• Defense +5
• Sp. Atk +15
• Sp. Def +5
• Speed +5
• Fire Spin Power +15
• Overheat Power +6
• Fire Spin Move Gauge Refresh 3
• Overheat Move Gauge Refresh 3 
• Hypnosis Move Gauge Refresh 3
• Can’t Stop Us! MP Refresh 3
• Dynamic  Entry
• Rude Awakening 5

Serena & Delphox are not as reliant on their sync grid as other sync pairs to make them useful. Even at sync level 1, they can find a place on your team with this basic build. Troublemaker as a lucky skill will help with Hypnosis’ accuracy.

Delphox’s prime use is to use Hypnosis to put the entire opposing field to sleep. The move starts out with 75 percent accuracy, so Dynamic Entry is picked up to make Delphox’s first attack a sure hit.

This build picks up the Move Gauge Refresh 3 for Fire Spin, Overheat, and Hypnosis as well as MP Refresh 3 for Can’t Stop Us! Refilling the move gauge is always handy and an extra use of Can’t Stop Us! can max Sp. Attack or remove a status condition later in the battle.

With the remaining energy, Rude Awakening 5 will power up Delphox’s sync move if the target is asleep. An extra +5 power to Fire Spin helps just a little bit if you use this sync pair for supplemental damage.

Trapped Fire Spin Build (Sync Level 2/5)

(build link)

Total Sync Orb Cost: 750
Total Energy Used: 60
Total Upgrades:

• HP +20
• Defense +10
• Sp. Atk +15
• Sp. Def +5
• Speed +20
• Fire Spin Power +15
• Overheat Power +3
• Fire Spin Move Gauge Refresh 3
• Hypnosis Move Gauge Refresh 3
• Fire Spin Mind Games 4
• Dynamic Entry
• Stationary Target 5

This build focuses on trapping opponents with Fire Spin. Opponents need to be awake for the trapped condition to cause damage, so having a sync pair to soak up damage is crucial. The Troublemaker lucky skill is recommended to boost accuracy.

Dynamic Entry will make Delphox’s first attack a sure hit. Using Hypnosis first gives you the chance to either use Can’t Stop Us! to boost accuracy or Fire Spin on multiple opponents. 

Hypnosis Move Gauge Refresh 3 and Fire Spin Move Gauge Refresh 3 help refill the move gauge bar since Delphox may only attack when you have the bars to spare from your primary damage dealer.

Fire Spin gains 15 power and Stationary Target 5 powers up moves when the target is trapped. Combined with Mind Games 4, Fire Spin will help any other special strike sync pairs deal more damage to the target by lowering the target’s Sp. Defense.

Impervious Overheat Sync Build (Sync Level 3/5)

(build link)

Total Sync Orb Cost: 750
Total Energy Used: 60
Total Upgrades:

• HP +10
• Defense +5
• Sp Atk +15
• Sp. Def +15
• Speed +5
• Overheat Power +6
• Overheat Move Gauge Refresh 3
• Hypnosis Move Gauge Refresh 3
• Dynamic Entry
• HP Advantage 4
• Impervious
• Stationary Target 5

With the entire sync grid unlocked, Serena & Delphox gain access to the Impervious passive ability. This negates Overheat’s drawback and this build aims to unleash damage upon opponents. Consider Troublemaker for accuracy or Critical Strike lucky skills for increased damage.

As with the other builds, Dynamic Entry ensures that the first attack–likely Hypnosis–will hit. Since Overheat costs three bars, both Hypnosis Move Gauge Refresh 3 and Overheat Move Gauge Refresh 3 are picked up. To keep opponents locked down and asleep, having enough move gauge is very important.

Impervious stops any of Delphox’s stats from being lowered, including any stolen with Stat Leech 4. Since Overheat no longer lowers Sp. Attack by 2, this sync pair sustains their destructive power.

Taking a moment to use Fire Spin upon an opponent leaves them trapped. Since you want to keep targets asleep, they won’t take damage from being trapped. Stationary Target 5 powers up all attacks against trapped opponents. 

Delphox’s passive ability Good Night-mare 5 powers up moves against sleeping targets. Finally, HP Advantage 4 will increase damage the more HP Delphox has. If all opponents remain asleep, Delphox should be at full health. With this build, Serena & Delphox can rival strike sync pairs in damage.