Trolls can be instantly killed by the sun. Trolls sundie:

• With link, in sunlit areas.
• Without link, in sunlit areas, when affected by Noquit or Novoid.

Trolls don’t sundie:

• Without link, in sunlit areas, when not affected by Noquit or Novoid.

These deaths are “permanent” and reduce the character to level one.

See also: Reborn