Why did the children of the forest create the night king?

Related questions

1. Why the night King is bran?
2. Was the first night king a stark?
3. Was the Night King originally a stark?
4. What did night King want?
5. Why Jon Snow is rightful heir?
6. Why was rhaegar killed?
7. Which Dragon does the night King get?
8. Was the first white walker a stark?
9. Can the White Walkers talk?
10. Is the Night King Bran the Builder?

Tags

1. #sacred
2. #background
3. #captured
4. #walker
5. #walkers
6. #first
7. #invaded
8. #trees
9. #slaughtering
10. #became
11. #westeros
12. #defend
13. #before
14. #white
15. #among
16. #cutting
17. #themselves
18. #forest
19. #their
20. #created
21. #children
22. #night