Well, how should I put this ... To me, VLR had more meaning to it, as you ended up succeeding with the first part of the plan and kept improving. In difference to that, ZTD focused more on "the things that need to happen in order for ZTD itself and VLR to work", such as Phi's and Delta's birth, the Radical-6 outbreak as told in VLR occuring in one of the endings, making sure that ... (cont.)