Kwolok helps Ori advance in their main quest in finding Ku by tasking them to purify the waters at The Wellspring in order to reach the Silent Woods.
After Ori and Ku's encounter with Shriek left the latter at death's door, Kwolok resolves in helping Ori restore the land by finding Strength of the Forest in Luma Pools. After he finds it, Kwolok becomes corrupted by the Stink Spirit, which previously resided in The Wellspring, and Ori is forced to fight him.
After Ori defeats Kwolok and the Stink Spirit, Kwolok frees himself from the vile creature's control and crushes it for good. However the toad guardian sustained fatal injuries from the battle, and with the last ounce of his strength, he requests Ori to watch over Niwen and the Moki. Kwolok then vanishes into light as he succumbs to his injuries.
Harrunk! A spirit in my Marsh? So the Moki were right. I wanted to believe...but it has been so long. I am Kwolok and you are welcome in my marsh, little one. The Moki tell me you seek your friend, an owlet. She fell far to the east. The Silent Woods hold her now. Where the owls are no more. Once the waterways behind led me there, but the waters have grown foul and impassable. There is one way, however. The Wellspring to the west, a great watermill, sits silent. Were you to set it's wheels in motion, the waters would flow clear once more. I would accompany you, but the Moki need me. I can give you something else, however. A fragment of the ancient light that once brightened these wilds. May it's voice be your guide through this perilous land.
After clearing Wellspirng
Welcome back, little one. The Moki tell me you have taught the clear waters to flow once more. The stench that once hung over the Wellspring is gone. Our Marsh is in you debt. The way east to the Silent Woods is now open, but beware. The one the Moki call Shriek lives there. Her heart is stone, her cry is pain. I pray you find your friend...before she does.
After Ku's injury
I am saddened for our friend. The Voice of the forest has done what it can, but its light is weak. Too many of us have suffered in these dark times. The smallest among us the most. With the Willow's End, the light shattered. The spirits perished, and our land fell to decay. The fragments of light were scattered, weakened... barely wisps. Left as they are, their light will fade forever. It is only a matter of time. But with the Moki's help, I have located where they fell. The forest's memory, bound by frost in the north. Its eyes, lost in darkness to the south. Its strength, drowned in waters to the west. Its heart, buried beneath the shifting sands to the east. And it's voice, who journeys with you. alone, they are weak. But brought together...if anything can undo the damage that has been done, it is the Will of the Wisps. No longer can I remain hidden in my hollow. I too will join the search. Farewell, little one. The Moki and I will help you where we can!