Competitive (High Investment)
As Stigmata and Echo can both rearrange their orbs, Echo's optimal spot is in the Blue slot of the team. Echo should avoid Yellow as it is best used by Rigor.
Echo acts as the starter of this team to set up the Amplifier Class passive while quickly closing the gap with a Yellow 3-Ping, simultaneously setting up Rigor’s QTE to benefit Stigmata. Echo should swap to Stigmata as soon as she has closed the gap. Superna Awakening Echo is necessary for this rotation opener. Without Superna Awakening, players should instead swap to Stigmata immediately.
Echo's SSS-Rank can potentially be obtained for free through the Tactical Assessment Manual (Battle Pass). As it is likely that many other players within higher tiers of competitive play will have obtained this, it may be an important consideration to make. Echo's Signature Weapon significantly improves this team, as it allows her to use Weapon Resonances and Weapon Harmonization.
As other slots are better used by other members, Stigmata takes the remaining position in the team.
Stigmata's SS3-Rank-serves as a potentially very high increase to her DPS potential, as pairing it with 2 set Cottie can allow Stigmata to perform multiple Signature Moves in quick succession before needing to switch out. Her Signature Weapon is strongly recommended for consistently high amounts of Stigmata Will stacks to improve her Signature Move's damage. Weapon Resonances also play a strong factor in this team, as Deadline Timing rises in priority to ensure Stigmata has enough orbs to consistently pull off multiple Signature Moves each rotation.
Optimal rotation for this composition makes use of Superna Awakening to allow Echo to begin combat with a guaranteed Yellow 3-Ping which she should use to start. As such, Rigor should be set on Yellow to allow for uninterrupted rotations while allowing Echo to trigger her QTE to further assist Stigmata. Superna Awakening Echo is necessary for this rotation opener. Without Superna Awakening, players should instead swap to Stigmata immediately.
Rigor's Leap should be considered a minimum investment for this team as it increases her DPS by a significant amount. Rigor should be at least SS-Rank in this composition, as the ability to reapply her Defense reduction debuff from off-field can greatly improve the team's potential output. SSS-Rank is not necessary, but can be potentially obtained for free through the Tactical Assessment Manual (Battle Pass). If accessible, it is highly recommended for the increase to her Defense reduction debuffs. Signature Weapon serves as another increase to Rigor's maximum Defense reduction and allows for Weapon Resonances.