Robin 
Harmony A Halovian singer who was born in Penacony and has risen to cosmic fame. An elegant and demure young lady. This time, she has been invited home by The Family to grace everyone with song during the Charmony Festival. She can use the power of "Harmony" to broadcast her music, manifesting "resonance" among not only her fans but all manner of lifeforms.
HP
ATK
DEF
SPEEDSupport Build
Best Light Cone
Robin Best Stats
Robin Best Substats
Robin Best Relics
Robin Best Teams
F2P Team
As a support, Robin brings the DMG boost and CRIT DMG buff for the party. Herta can do Follow-Up Attacks and can benefit from the CRIT DMG buff during Robin's Concerto state. Herta can be replaced by any F2P DPS character. Even though Robin won't benefit much from the SPD buff, Asta can give even more ATK for her and buff the SPD of her other allies. Natasha or any F2P sustain character would work as the last party member.
Follow-Up Attack Team
Robin works well in a Follow-up Attack team since they attack multiple times in a single turn, which helps Robin regenerate Energy and also dish out extra damage during Concerto. With Robin's ATK and CRIT DMG buffs, Feixiao and Cipher can dish out even more damage. Aventurine acts as the sustainer and provides even more buffs and shields for them, so this is a very solid team.
Hypercarry Team
The team composition above is just an example of a Hypercarry team. Since Robin is a universal Harmony character, you can slot her in with any Hypercarry team composition and make it work thanks to her amazing offensive utility. The extra damage she deals during the Concerto state is the icing on the cake. You can use any Hypercarry DPS that scales with ATK for this such as The Herta, Jingliu, Jing Yuan, and many others. Her party-wide ATK, CRIT DMG, and DMG buffs are all great for DPS characters. On top of that, she gives all allies an extra turn after using her Ultimate which means your other Harmony character can buff your DPS again, and make them attack again.
DoT Team
Thanks to Robin's ATK and party-wide DMG buff, she can synergize well with DoT characters like Black Swan and Kafka while also providing them an extra turn with her Ultimate. Black Swan and Kafka will deal even more damage with their DoTs. Huohuo can restore Energy for the whole team which helps Robin's Ultimate get back up much sooner while also providing even more ATK.
Skills
Deals Physical DMG equal to #1[i]% of Robin's ATK to one designated enemy target.
Increase DMG dealt by all allies by #1[i]%, lasting for #2[i] turn(s). This duration decreases by 1 at the start of Robin's every turn.
Robin enters the "Concerto" state and makes all teammates (i.e., excluding this unit) immediately take action. While in the "Concerto" state, increases all allies' ATK by #1[f1]% of Robin's ATK plus #3[i]. Moreover, after every attack by ally targets, Robin deals Physical Additional DMG equal to #4[i]% of her ATK for 1 time, with a fixed CRIT Rate for this damage set at #5[i]% and fixed CRIT DMG set at #6[i]%. While in the "Concerto" state, Robin is immune to Crowd Control debuffs and cannot enter her turn or take action until the "Concerto" state ends. A "Concerto" countdown appears in the Action Order. When the countdown's turn begins, Robin exits the "Concerto" state and immediately takes action. The countdown has its own fixed SPD of #2[i].
Causes the target being hit to take extra DMG, which is not considered an attack.
Freeze, Entanglement, Imprisonment, Dominance, Outrage, Strong Reverberation, Alien Dream, Snarelock, Terrified, Action Lock, Happiness Puppet, Grudge Ablaze.
Increase all allies' CRIT DMG by #1[f1]%. Moreover, after allies attack enemy targets, Robin additionally regenerates #2[i] Energy for herself.
After using Technique, creates a Special Dimension around the character that lasts for #1[i] seconds. Enemies within this dimension will not attack Robin and will follow Robin while the dimension is active. After entering battle while the dimension is active, Robin regenerates #2[i] Energy at the start of each wave. Only 1 Dimension Effect created by allies can exist at the same time.
Traces
Eidolon
While the "Concerto" state is active, all allies' All-Type RES PEN increases by
When dealing DMG, ignore a part of the enemy target's resistance to the corresponding damage type.
While the "Concerto" state is active, all allies' SPD increases by
Skill Lv. +2, up to a maximum of Lv.
When using the Ultimate, dispels Crowd Control debuffs from all allies. While Robin is in the "Concerto" state, increases the Effect RES of all allies by
Freeze, Entanglement, Imprisonment, Dominance, Outrage, Strong Reverberation, Alien Dream, Snarelock, Terrified, Action Lock, Happiness Puppet, Grudge Ablaze.
Basic ATK Lv. +1, up to a maximum of Lv.
While the "Concerto" state is active, the CRIT DMG for the Physical Additional DMG caused by the Ultimate increases by
Causes the target being hit to take extra DMG, which is not considered an attack.