MORE CO OP DETAILS:

Co-Op Agent Reworks - Astra
Astra appears to have modified versions of her Tactical Prisms granted to her when played in Co-Op. From what I can gather:

For every 20 Energy consumed, Astra Yao gains 1 stack of Starlight, up to 3 stacks. During Idyllic Cadenza, hold to unleash Basic Attack: Radiant Moment, continuously channeling an energy beam to attack enemies for up to 10s. Upon activating this skill, Starlight will be consumed, and with each stack consumed the skill duration will extend by 1s. During this skill, Anti-Interrupt Level is increased to 6, and DMG taken is reduced by 80%. When the skill hits enemies, the target's DEF is reduced by 30% for 10s and all teammates recover 15% of their Max HP. The HP recovery can be triggered once every 10s. When Astra Yao's Basic Attack: Interlude hits enemies, it will consume 20 additional Energy, and when Basic Attack: Chorus hits enemies, it will restore 25 additional Energy.
Keep in mind this is just based on what I can understand as I haven't looked too deeply at HZ Gear / Tactical Prisms. There may be changes or things I have misinterpreted but the structure looks the same as this Tactical Prism...