User blog comment:Worldentertainment5/Which should I choose: Legend World(knights) or Darkness Dragon world (purgatory knights)/@comment-25061243-20141010143737

DDW if you're going budget since the new trial deck is out as well. So it'll be easier to build a deck. Plus BT05 will have more support of Darkness Dragon world in the future while legend world will have to wait for the Special Set.

In the end it's up to you. Both have their pros and cons.