Like an arrow loosed from a string, Nakoa shot forward through the water and arced around the beast, propelled with unnatural speed and strength. He corkscrewed to avoid the swiping tail, the current shoving him dangerously close to the rocks. But the beast was simply angry and quite focused on the little being intruding on its mind. Nakoa didn't know how long Arla could keep it from turning on her, but he hedged toward a minimal time. Monsters of the deep were dangerous things in both body and will.
The Wrean disappeared, scraping through a tunnel across the way and out of sight. This left Arla alone in the dark waters facing down a being that'd be perfectly pleased seeing her crushed in its jaws or smeared across cavern walls. It actively fought her attempts at control, taking an active effort for the Nightsister to keep her hold. Red was its rage, long-lived and well-aged in the spirit waters of Lake Natth. Which were unfortunately a problem all their own.
They were only rotted pieces, shredded to slivers by time, but sleeping spirits they were still. The longer Arla wielded her magic, the more they were stirred from rest and spread rage in their wake. For a time, Arla had to weather these things alone as Nakoa searched for the path forward.
Then there came a sound from the other side of the cavern, a melodic hum in dual tones steadily in volume until it matched the thrashing of water. "Irirangi yatahadathu!" Blue-purple lights streamed through the dark water, illuminating shredded souls ordinarily only visible through the second sight like sunlight through thin paper. "Astamae alan, 'arwah albuhayrati. Astamae 'iilaa 'ughniat alma' wastaraha." Arla would see where spirits had latched onto the beast, expressing their rage through it and empowering its will. "Laqad tahadath Irirangi."
Now some let go and floated through the water, dispersing. Other strays began to drift toward Nakoa, drawn by his humming voice. This left him busy and was difficult work, but Arla would likely find her own task easier without angry spirits reinforcing her target of control.
@Phoenix