Highlighted weapons are free options.
Ineffa transforms all instances of the Electro-Charged reaction into Lunar-Charged while she's in the team, which has its own scalings and can even crit. Both her Skill and Burst deploy her robot companion, Birgitta, to the field, who can deal damage and apply Electro while off-field. Additionally, Ineffa's Skill can also provide a shield. Her Burst also provides an Elemental Mastery buff based on a portion of Ineffa's ATK (her A4 talent).
Birgitta stays on-field longer than both of Ineffa's Skill and Burst individual cooldowns, meaning that Birgitta has 100% field uptime.
Ascendant Gleam assumed here; Ineffa uses Burst every other rotation unless she uses an ER weapon.