Lon'qu

Weapon: Solitary Blade (+Eff)
Assist: Reposition / Flexible
Special: Noontime / Sol
Passive A: Distant Counter 
Passive B: Repel / Close Call
Passive C: Pulse Smoke / Spd Smoke / Atk Smoke / Flexible
Sacred Seal: Swift Stance / Darting Stance 

• This build allows Lon’qu to shine in a defensive role, focusing on his ability to tank hits through Speed stacking; a +SPD IV is accordingly ideal here, as well as largely non-negotiable. 
• Repel and Close Call are recommended to convert his Speed into tanking power, reducing the damage he takes based on how much faster he is than his opponent; combined with Distant Counter, this capacitates Lon’qu to confidently counter on a wide breadth of foes. 
• Solitary Blade’s built-in Slaying effect proves useful here to quickly activate healing Specials for improved survivability. Noontime is the natural choice here as its low cooldown lets Lon’qu use it on every counterattack in Enemy Phase, but Sol may be considered if provided with accelerated cooldown support. 
• Smoke skills further develop his proficiency at tanking and should be taken here. For Aether Raids, Pulse Smoke is ideal -- otherwise, Atk Smoke or Spd Smoke are better for their generally greater applicability. Defensive seals that increase his Speed (i.e. Swift Stance and Darting Stance) complement this build. 

Weapon: Solitary Blade (+Eff)
Assist: Reposition / Flexible
Special: Galeforce 
Passive A: Flashing Blade 4 / Atk/Spd Solo / Swift Sparrow 
Passive B: Null Follow-Up / Wings of Mercy / Close Call / Repel
Passive C: Def Smoke / Spd Smoke / Flexible
Sacred Seal: Swift Sparrow / Darting Blow / Flashing Blade 

• A standard Galeforce setup meant to allow Lon’qu to maximize his maneuverability in the Player Phase and potentially take down multiple foes in one sitting. A +SPD IV is crucial here to ensure his follow-up attack and strengthen Flashing Blade’s consistency, but +ATK may also be considered if unavailable. 
• Solitary Blade’s built-in Slaying effect enables Lon’qu to activate Galeforce in a single engagement when equipped with Flashing Blade (provided he doubles), making the skill crucial to his success. It can be used in either his A slot or as a seal; pairing it with skills like Swift Sparrow and Darting Blow helps solidify its effectiveness. 
• For his B slot, Null Follow-Up further assists Lon’qu in ensuring his follow-up attack, negating skills that would otherwise prevent it. Mobility-based options like Wings of Mercy also complement this build’s intended playstyle, with Close Call and Repel being notable options for their added damage reduction. 
• Smoke skills pair well with Galeforce set-ups to debilitate nearby foes and make them easier to KO in subsequent rounds of combat; Def Smoke or Spd Smoke is ideal to strengthen his combat prowess. 

Weapon: Solitary Blade (+Eff)
Assist: Reposition / Flexible
Special: Moonbow / Luna
Passive A: Swift Sparrow / Atk/Spd Solo / Fury 
Passive B: Null Follow-Up / Lull Spd/Def / Wrath
Passive C: Even Spd Wave / Odd Atk Wave / Flexible
Sacred Seal: Swift Sparrow / Sturdy Blow / Darting Blow 

• Lon’qu can also perform quite well with a more generalist offensive setup. Increasing either his Attack or Speed is preferred here to maximize his effectiveness. 
• Moonbow is a great Special choice for its frequent (and consistent) activation rate, though Luna can be considered should one favor stronger burst damage in exchange for having a slightly longer cooldown. 
• Offensive A slot skills and seals such as Swift Sparrow and Sturdy Blow are fantastic options that supplement the Solitary Blade’s combat prowess in the Player Phase. With regard to his A slot specifically, Atk/Spd Solo is notable for its ability to remain active in both Phases. 
• Lon’qu has a flexible B slot here. Null Follow-Up is a good generalist choice that helps break through effects that would otherwise hamper his offensive presence, Lull Spd/Def is highly useful to break through enemy bonuses, and Wrath grants improved burst damage and pairs well with Moonbow. 
• Similarly, this build’s C-slot is flexible as well, though Attack or Speed-increasing Wave skills are always solid candidates to make Lon’qu more self-sufficient.