Arknights CA-4 rewards Skill Summary books which are used for operator skill rank ups.
Aerial Threat is available on Tue/Wed/Fri/Sun
Recommended Operator Elite 1 Lv. 35.
Here are the operators used in this example:
- 2x Sniper (ST)
- 1x Sniper (AoE)
- 1x Caster (ST)
- 1x Caster (AoE)
- 2x Healer
- Shaw (with Rank 4 skill)
- Caster (ST) in position (A) facing right. Our caster will help deal with the Raptor that has higher DEF.
- Healer in position (B) facing left.
- Sniper (ST) in position (C) facing right.
- Sniper (AoE) in position (D) facing right.
- Healer in position (E) facing left.
- Sniper (ST) in position (F) facing right.
- Shaw in position (G) facing down.
Shaw will help push Airborne Soldier Leader off the ledge.
At 24 Kills you can return Shaw and replace her with your Caster (AoE) in position (G) facing right.