Fallen Takumi

Weapon: Skadi (+Eff) / Skadi

Assist: Rally Atk/Spd+ / any Rally / flexible

Special: Moonbow / flexible

IVs: +HP or +Atk or +Spd / -Def or -Res

Passive A: Life and Death / C Duel Infantry / HP +5 / flexible

Passive B: Atk/Spd Ruse / any Ruse / Sudden Panic / any Snag / any Link / any Chill / flexible

Passive C: Infantry Pulse / flexible

Sacred Seal: Life and Death / HP +5 / Def Feint / flexible

• Skadi (+Eff) is a disappointing refine in many ways. However, it does still possess a unique and interesting support effect, applying 7 damage and Panic status to foes within the 3 columns centered on Takumi at the start of turns 2 and 3. This build attempts to capitalize on that by adding other support capabilities. 
• While Skadi (+Eff) provides the damage and Panic effect on turns 2 and 3, compared to just turn 3 for Skadi, the base version of the weapon does deal 10 damage as compared to the refine’s 7, so there is an argument for using either. The extra combat capabilities of Skadi (+Eff) generally do not affect Takumi’s performance as a support unit unless he needs to deal with an enemy that the unit he is supporting cannot. 
• The crux of this build is using a Rally in combination with a Ruse to apply stat debuffs and the Guard status (slowing Special charge) to any allies in the same column as Takumi or the target of his Rally. Any Rally and Ruse can be used for this, and the ideal choice will depend on the unit you are using him to support. For a debuff in an extra stat, a Feint seal such as Def Feint can be added as well. 
• If the Ruse effect is not available or not desired, Takumi can use another effect such as Sudden Panic, Chill Atk, Atk/Spd Link, Spd/Res Snag, or any other variant of any of those skill types to provide other types of support. If a Ruse is not used, a positional assist such as Reposition or Smite may be more useful than a Rally. 
• If using Takumi as a support unit in Arena, C Duel Infantry is highly useful to increase his scoring potential. In Aether Raids, Life and Death A and seal may be useful in order to increase his visible Atk and Spd in order to be the target of Bright Shrines in lieu of a teammate. HP +5 can be useful if using a skill that compares his HP to another unit’s such as Panic Ploy or Infantry Pulse. Otherwise, options that boost his combat potential like Fury are a decent choice. 
• Takumi has a few choices of C slot available to support a team. Panic Ploy allows him to apply a directional Panic debuff to foes within the same row or column as him on every turn, allowing coverage outside of Skadi (+Eff)’s effect. Infantry Pulse is useful if he’s on a team with other Infantry allies that want reduced Special charge on turn 1, such as Duo Alfonse. Infantry Rush, Infantry Flash, or Infantry Breath could also be used to support other Infantry. Joint Drive Atk is a great support option that boosts his own Atk and the Atk of any allies within two spaces of him by 4, so long as there is at least one ally within two spaces of him. This slot is flexible; there may be other good options depending on the team. 

Weapon: Skadi (+Eff) 

Assist: flexible

Special: Moonbow / flexible

IVs: +Atk or +Spd / -Def or -Res or -HP

Passive A: Atk/Spd Push / Swift Sparrow / flexible

Passive B: Lull Spd/Def / Null Follow-Up / Desperation / flexible

Passive C: Time’s Pulse / Joint Drive Atk / Savage Blow / flexible

Sacred Seal: Blade Session / Swift Sparrow / Savage Blow / flexible

• Skadi (+Eff) gives Takumi a conditional +5 Atk/Spd and deals 7 damage to his target and foes within two tiles of his target after combat. This build attempts to capitalize on those by emphasizing his offense. 
• Moonbow is chosen as the Special for its combination of low cooldown and damage that increases based on foe’s Def. 
• The listed choices of A skill and seal boost Takumi’s Atk and Spd to help him double and do higher damage. Blade Session provides either a +3/+3, +6/+6, or +9/+9 boost depending on whether 0, 1, or 2+ units on the team are alive and have ended their turn before Takumi. 9/9 is currently the highest boost in Atk and Spd available from a seal, and the condition is not too difficult to meet. Otherwise, options such as Swift Sparrow and Atk/Spd Push are solid choices. Savage Blow seal is also an option to increase Takumi’s after-combat chip damage even more. With Savage Blow C and seal, he does 21 damage to any units with two spaces of his foe after combat. 
• Lull Spd/Def provides a debuff of 3 to Takumi’s foe’s Spd and Def while also nullifying any visible buffs the unit has in those stats, effectively increasing Takumi’s damage and ability to double. Null Follow-Up is also a useful option that allows Takumi to disable any effects that guarantee his foe’s follow-up attacks and block his own, meaning that he should generally get a follow-up attack against most units, other than the particularly fast. Desperation is a great budget option that allows Takumi to follow-up before his foe can counter, so long as he can follow-up and he is below 75% HP at the start of combat. 
• Time’s Pulse is a useful C slot that charges Takumi’s Special by 1 if it is at max cooldown at the start of his turn. Joint Drive Atk boosts his Atk and the Atk of any allies within two spaces of him, so long as there is at least one ally within two spaces of him. Savage Blow provides extra after-combat damage, as mentioned previously.