Lachesis

Weapon: Dazzling Palm Staff+ / Dazzling Tannenbaton+ / Dazzling Rapport Wand+ / Flexible

Assist: Restore+ / Rescue+ / Flexible

Special: Imbue / Heavenly Light / Flexible

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

Passive A: HP +5 / Fortress Res / Flexible

Passive B: Sudden Panic / Even Pulse Tie / Sabotage Atk / Flexible

Passive C: Distant Guard / Drive Atk / Flexible

Sacred Seal: Distant Guard / Drive Atk / HP +5 / Flexible

• Lachesis can opt to run a support-based Staff to help her teammates, of which there are several good options. Palm Staff+ is a great option if she’s supporting armored units using skills like A/R Far Save and A/D Near Save, since she can stand in enemy range, lower nearby foe’s Atk and Spd by 5, an effect which remains active even if she is “behind” an active Save unit. If she is being used to support other types of units, Tannenbaton+ is a great option that provides a minor stat boost and the Guard effect to nearby allies. Other options like Flash+ and Gravity+ can provide useful effects as well, but many of them require Lachesis to attack to activate the effect, which is sometimes difficult to do safely. 
• Lachesis’s other skills are chosen to focus on healing, buffing her allies, and debuffing her enemies. Restore+ is a great Assist, since it allows her to heal her allies while also curing them of any negative status effects like Panic. Rescue+ is another great choice that provides healing as well as a movement effect similar to Reposition. 
• The B skill is flexible. Sudden Panic targets foes with less HP than Lachesis, applying the Panic status to any that are adjacent to another foe at the start of her turn. If Sudden Panic is used, HP +5 is a good choice of A skill and seal to allow Lachesis to target units with higher HP. Even Pulse Tie provides a different HP-based effect, targeting foes whose Special is ready at the start of every even-numbered turn, and increasing their Special count by 2. This can be very useful against teams that rely on precharged Specials. Sabotage Atk (or another Sabotage) skill can also be useful, to debuff foe’s Atk at the start of each turn if they are adjacent to another foe and have a bit less Res than Lachesis. If a Sabotage B skill is used, Fortress Res is a good choice of A skill and Phantom Res is a good seal. There are plenty of other B skills that can also provide valuable support options. 
• The C skill is also flexible, and depends on the needs of the team, with Distant Guard and Drive Atk being two options that benefit many units. 
• The boon and bane are also flexible and may be chosen based on Lachesis’s skills: HP boon if using Sudden Panic or Even Pulse Tie, Res boon if using a Sabotage, or Atk boon to slightly increase the amount she heals. Def and Spd are generally not useful stats for this build, so they are good choices for bane. 

Weapon: Wrathful Staff of Tribute+ / Wrathful Palm Staff+ / Wrathful Absorb+

Assist: Martyr+ / Flexible

Special: Miracle / Flexible

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

Passive A: Atk/Def Ideal / Atk/Spd Ideal / Flexible

Passive B: Dazzling Staff / Lull Atk/Res / Flexible

Passive C: Joint Drive Atk / Time’s Pulse / Flexible

Sacred Seal: Atk/Spd Solo / Flexible

• While Lachesis’s statline and weapon do not make her a top choice for combat, she can still prove somewhat effective with the right skills. 
• Staff of Tribute+ provides a boost of 6 Def and Res in-combat and restores 7 HP to Lachesis and allies within 2 spaces after combat so long as there is at least one ally within 3 spaces. Palm Staff+ provides a similar effect to Atk/Spd Rein, debuffing the Atk and Spd of enemies within 2 spaces of Lachesis. Both of these effects help her survivability in combat. Absorb+ is also an option to provide some self-healing, but it is considerably weaker than the other options. 
• Miracle, once charged, allows Lachesis to survive one hit that would KO her and remain alive on 1 HP. This is a powerful effect, but it charges slowly. Using a C skill like Time’s Pulse can charge it slightly faster. Alternatively, Joint Drive Atk provides a boost fo 4 Atk for Lachesis and any allies within 2 spaces so long as there is at least one ally within 2 spaces. 
• The A skill is flexible depending on whether you wish to improve Lachesis’s damage, Spd, or bulk. Various skills like Atk/Def Ideal and Atk/Spd Solo provide useful stat boosts. 
• Dazzling Staff is a good B skill that denies counterattacks from all units when Lachesis initiates, unless those units have Null C-Disrupt or a similar effect. Wrathful Staff is also an option for use with the Dazzling refine on whatever staff Lachesis is using. Other skills like Lull Atk/Res can also be used to increase Lachesis’s stats or decrease her enemies’ stats.