It stands for 'Build A Dino' by the way.
I was watching BruisedByGod stream a 'big dinos' brewing session, and felt that the deck needed an extra dose of inconsistency. To that end, I added a shadow splash (pretty much solely for Dark Return) and more combo/puzzle-ey cards like Second Sight / Twinning Ritual to leverage the echo units and give the deck some interesting extra options turn to turn.
Definitely a fun casual queue deck. You're a braver player than I if you take this to ladder.