Matthew

• Preferred IV: +ATK or +SPD / -RES or -HP
• Weapon: Barb Shuriken+ (+Spd) / Lethal Carrot+ (+Spd)
• Assist: Reciprocal Aid / Draw Back
• Special: Ignis / Bonfire / Luna
• Passive A: Swift Sparrow / Life and Death
• Passive B: Desperation 
• Passive C: Hone Spd / Threaten Spd / Flexible
• Sacred Seal: Speed +3 / Attack +3

While not his main forte, Matthew may opt to change from a helpful spy into a full-on assassin. Benefiting from his 4-point Attack superboon, the 12 might of a Speed-refined Barb Shuriken or Lethal Carrot, the boost of Swift Sparrow, and a Speed +3 seal, Matthew manages to reach an acceptable 45 Attack and 43 Speed when initiating attacks. When attacking an enemy already debuffed, this Attack increases to an effective 52, which can really hurt when paired alongside a 24 damage Ignis proc (34 with Lethal Carrot). An Attack +3 seal changes that to 48/40, if one finds 45 Attack too low for comfort.

Life and Death can be used to add an extra point to his Attack and Speed, plus allow him to retain the Speed on Enemy Phase, though this does weaken the burst power of his Ignis. In such a case, Bonfire or Luna should be used to take advantage of their quicker cooldowns.

Desperation allows him to attack twice without retaliation, and can be set up by taking an advantageous physical hit or with his native Reciprocal Aid. 

For his C slot, any Hone (such as his native Hone Spd), Spur, or Drive can work well to suit his team's needs. While Matthew is not at all a frontliner, Threaten Spd can be safely applied to melee targets, complementing his job as a debuffer and helping him out against speedier targets. 

• Preferred IV: +SPD / -HP or -RES
• Weapon: Smoke Dagger+ (+Spd)
• Assist: Ardent Sacrifice / Reciprocal Aid / Draw Back
• Special: Bonfire / Miracle
• Passive A: Darting Blow / Armored Blow
• Passive B: Watersweep / Windsweep / Renewal
• Passive C: Drive Spd / Drive Def / Spur Spd / Flexible
• Sacred Seal: Drive Atk / Drive Def / Spur Spd

An all-in support set that aims to cripple his opponent's stats and absolutely ensue that matchups are incredibly skewed in the favor of his teammates.The crux of this set is the refined Smoke Dagger, which reduces all four stats of his target and their allies within two spaces by 6. Matthew's goal here is to push this advantage as far as he can by also boosting an ally afterwards with a Drives or Spurs allowing them clean up with relative ease.

Using Spur Spd, Matthew can create a Speed swing of up to 14 points, though Drives are usually preferred for their looser positioning requirements. The choice of stat for his Drives/Spurs is actually rather flexible, with Atk, Def, Res, and any dual Spurs also being great choices to help allies hit harder or tank up.

For his assist, Ardent Sacrifice or Reciprocal Aid can be utilized to give Matthew the ability to heal his allies in cases when he is unable to attack. Elsewise, a standard movement assist can be taken to shuffle allies into good positions and attack while in range of his buffs.

Bonfire is Matthew's Special of choice to add some burst damage. Miracle is a gimmicky alternative that can give Matthew strong bait potential once it is charged, surviving anything on Enemy Phase and inflicting debuffs for the following turn.

Darting Blow is the preferred A skill, helping ensure the success of Watersweep even against super fast mages like Nino. Watersweep lets Matthew prevent counters from the largest number of ranged enemies as possible, including the increasingly popular dragons. Windsweep can be taken instead to secure matchups against Distant Counter units, though typically Matthew is not as uncomfortable taking physical hits, so long as they do not retaliate twice.

If one is not a fan of sweep skills, instead consider Renewal to give Matthew some longevity and nice synergy with Reciprocal Aid. This can be paired with Armored Blow to more safely brush off Distant Counter hits and give him a fair chance to live even when doubled back.

• Preferred IV: +SPD / -RES or -HP
• Weapon: Rogue Dagger+ (+Def)
• Assist: Draw Back / Reciprocal Aid
• Special: Bonfire / Ignis
• Passive A: Fury / Defense +3
• Passive B: Quick Riposte / Poison Strike
• Passive C: Atk Smoke / Hone Spd
• Sacred Seal: Speed +3 / Defense +3 / Poison Strike

A low investment set that requires no inherits from heroes unable to be obtained as 3 star units.

Here Matthew's Defense is prioritized so that he can toss back hard hitting Specials, similar to budget Felicia builds that do the same with her Resistance, with his Speed given just light attention for the purpose of denying enemy doubles.

Quick Riposte ensures that he is always throwing out two attacks on Enemy Phase. Matthew wants to make sure to proc his Special on Enemy Phase in order to make the most of his Rogue Dagger buff, as it wears out at the beginning of every Player Phase, regardless of when it was applied.

For an even cheaper B slot alternative, Poison Strike can be kept to ensure steady chip damage between Specials. Paired with a Poison Strike Sacred Seal, Matthew can really wear on high-Defense tanks.

Atk Smoke helps him debuff enemies further and tank up quite well. His default Hone Spd is already quite useful, of course.