The tainting of the waters began the shattering, them being the "base" of the plane.
after chapter 9, Korinthine went insane from the blessing of eyes, turning to all but killing herself in order to stop it.
Nhaulik consumed the waters as a whole, essentially becoming the most powerful of the three in quick succession, at the cost of mortal humanity
After Nhaulik regained consciousness, he went to Korinthine to tell her about its new power, unaware of the infection she had incurred.
When the Great Messiah was first proverbially birthed from the womb of the blooming messiah, the same minute was when Korinthine cast Nhaulik into the flame of izalith, which was partially why the tree grew so big.
By chapter 13, Nhaulik had been incinerated, yet due to its undeath, it managed to survive the lava, crawling out agonizing second by second.
Luwarin was so deluded by his idea of fantasy he truly thought he was doing the right thing, furthermore he was so deluded by depression, he thought he was doing the right thing.
the bridge still remains, though in a hollowed state.
Wes wrote *most* of what you've read, particularly the parts where Iron is involved.
Unlike the mushrooms attained by Dreamer, Luwarin's does not entail soulbinding.