Summer Sylvain

Weapon: Gronnblade+

Assist: Draw Back / Flexible 

Special: Glimmer / Draconic Aura

Passive A: Swift Sparrow / Atk/Spd Solo / Atk/Spd Push / Fury

Passive B: Desperation / Lull Spd/Res / Chill Spd / Chill Res

Passive C: Rouse Atk/Def / Hone Cavalry / Flexible

Sacred Seal: Swift Sparrow / Death Blow / Heavy Blade

• Summer Sylvain’s solid Attack and Speed values combined with his cavalry status makes him well suited for an offensive role, and this build capitalizes on just that by equipping him with a Blade tome for a massively higher damage ceiling. An Asset to either of Sylvain’s offensive stats is ideal here to maximize his potential.
• For his Special, Glimmer is a standard on Blade tome users for its low cooldown and fantastic synergy with the additional damage provided by Gronnblade’s effect, and Sylvain is no exception. Alternatively, Draconic Aura can be paired with the Heavy Blade seal to effectively bypass the Special’s otherwise long cooldown; this allows for more consistent and powerful Special activations.
• Any offensive A slot skill is recommended here, with Sylvain’s best options including Swift Sparrow, Atk/Spd Solo, Fury, and Atk/Spd Push 4. His B slot should similarly share an offensive focus, though he does have a variety of options available thanks to his solid overall bulk. Besides the standard Desperation, Sylvain can also take Lull Spd/Res to break through enemy bonuses, or a Chill to debilitate opponents and provide some support to his allies. 
• Sylvain’s C slot is flexible, though self-buffing skills like his native Rouse Atk/Def for greater self sufficiency and class-exclusive buffs are always good choices. Seals that enhance his offensive stats like Swift Sparrow and Death Blow are natural fits here.

Weapon: Melon Float+ (+DEF) / Sandwiches!+ (+Def) / Gronnowl+ (+DEF)

Assist: Draw Back / Flexible

Special: Sol / Bonfire / Moonbow

Passive A: Close Foil / Close Counter

Passive B: Lull Atk/Res / Lull Atk/Spd / Guard / Quick Riposte

Passive C: Atk Smoke / Res Smoke / Flexible

Sacred Seal: Quick Riposte / Sturdy Stance / Fierce Stance / Steady Stance

• This build takes a vastly different approach to Sylvain’s playstyle and focuses on his ability to tank hits and mitigate damage, rather than on his offensive capabilities. Accordingly, besides +ATK (for stronger healing potential) or +SPD (to avoid follow-up attacks), a +DEF IV may be considered to increase Sylvain’s physical resilience. 
• Sylvain’s weapon choice is flexible depending on what is available and personal preference. His native Melon Float is a great choice for its built-in healing and ample boost to his Attack and Resistance, though it does come at the cost of only working for one combat in each phase. Alternatively, Sandwiches! can be used for its consistent boost to both of the same stats in the Enemy Phase (but it lacks healing), or Gronnowl to enhance his entire statline in exchange for requiring constant ally adjacency for best results. 
• He can make great use of Sol to enhance his defensive capabilities through consistent healing, allowing him to mitigate any damage he may have taken. For more damage oriented options, Sylvain can utilize Bonfire for its consistent damage or Moonbow for its frequent activation rate. 
• The ability to counteract against range is crucial to maximize Sylvain’s versatility, so either Close Foil (with this being the preferable option) or Close Counter should be equipped for his A slot. Lull skills are excellent B slot candidates to negate enemy bonuses (particularly Attack buffs) but given their scarce availability, Guard or Quick Riposte are also valid alternatives. 
• Smoke skills pair well with this build’s defensive nature to debilitate his opponents. Atk Smoke and Res Smoke are especially notable to enhance his survivability and damage output respectively. For his seal, Quick Riposte is necessary to ensure his follow-up attacks in the Enemy Phase, but stat-increasing seals can be taken if Quick Riposte is already taken as his B slot skill.

Weapon: Gronnblade+

Assist: Draw Back / Flexible

Special: Glimmer / Moonbow / Miracle

Passive A: Close Foil / Close Counter

Passive B: Vantage

Passive C: Pulse Smoke / Res Smoke / Flexible

Sacred Seal: Fierce Stance / Brazen Atk/Spd

• Although this build once again sees Summer Sylvain make use of a Blade tome, this setup focuses more on his Enemy Phase performance and his ability to consistently land OHKOs; this sees particularly good use in Aether Raids Offense. A +ATK IV is naturally the best option here to further develop Sylvain’s OHKO potential. 
• The key strategy for this build is to pair Vantage and a skill that enables counterattacks regardless of range to cleanly sweep through all enemy types in the Enemy Phase upon losing enough HP. For use in Aether Raids Offense specifically, Close Foil is preferred given how uncommon dragonstone users are on defense teams (and it comes with an Attack boost to boot), but Close Counter can still be used to stay on the safe side. 
• Low cooldown options like Glimmer and Moonbow are always recommended Special options for their frequent activation rate, though Miracle can make for a worthwhile consideration to provide him some survivability since Vantage requires low HP and taking damage isn’t always avoidable. 
• Smoke skills shine here once again; Pulse Smoke is ideal to shut down Infantry Pulse setups in Aether Raids, otherwise Res Smoke is better to increase Sylvain’s damage. Most Attack-increasing seals will work perfectly fine here, such as Fierce Stance and Brazen Atk/Spd.