User blog comment:Tagion/BF D.I.P. - Finding a strategy/@comment-11454852-20150112143909

Personally, I feel a "key card" isn't as vital here as in Vanguard, there the Key Card is easy, your main G3, but here monsters don't stay on the field forever unless you're using Ancient World so relying entirely on one specific card every time doesn't sound that reliable specially since here the deck isn't digged as quickly as in VG.