1/Obel quest
Find 4 stone (there are some clues when you talk to the shadow near Obel lake)
When you have them all you will have a sentence "Morph plain has treasure"
Below Trabia Canyon is Morph plain ,walking around and hear some rocks say .Following instructions and you will find a "three stars"
2/Doomtrain quest
Find these items
5 Steel Pipe
5 Remedy+
5 Malboro Tentacle
and The Salomon Ring
then use Salomon Ring to get Doomtrain


Hope you will find out for yourself