The answer to thy question is thus:

Thou shall go to the 'Island closest to Hell' and the 'Island Closest to Heaven'. These islands are located on the east and west extremes of the world map.

Then, thou shall fight many hard bastard creatures. Thou shalt have already learned 'mug', thou will find it very useful!

Thy enemies will droppeth star fragments sometimes.

Adamantine? Me thinks you can refine 10 of them from a card, but I forget.

Questions to ask does thee?
Then feel free to ask me!