[ ] …And Cai Renxiang rose into the sky, and let loose with her Mothers Light, her light. In this nightmares of stagnancy she could feel her opposite. They would come to snuff her out, in exclusion of all else, relieving the other parties involved at cost to herself.
Lures the enemy from other defensive/engagement priorities, allowing more operational flexibility, at the cost of personal danger. Real chance of that freed up flexibility collapsing into unit commitments trying to keep Renxiang alive, in which case they're fighting on more exposed terrain.
[ ] …And Cai Renxiang remained on the earth, letting loose her light with caution, in close coordination with the harried White Plumes left in the lower valley away from the conflict raging on the cloven mountain. Relying on their defenses to preserve what was important, until the tide receded.
Less aggressive approach, defenses and units are strained more uniformly, not allowing as much flexibility in response but also not exposing any segment of forces to heightened stress. Something that stands out to me which I haven't seen other people discuss is that it does look like Renxiang will be drawing in nightmares with her light to some degree, matched to the endurance/kill-rate of those she links up with. She's still taking pressure off of the whole in this option, just much much more reservedly.
Ultimately, my choice is
[X] Killer_Whale