When your library is empty, the discard pile becomes the library (unless you've gone through the library three times already)
Toolcraft Exemplar is generally going to be worth three points of power, two points of toughness, and the single body printed on the card
After the Duel, he came across Luna, Leo, Yanagi, and Tanner leaving the building
Once per turn, during your Main Phase: You can remove 1 Morph Counter from your field, and if you do, Special Summon 1 "Gadget Box Token" (Machine/EARTH/Level 1/ATK 0/DEF 0)
It may be on the more expensive side once you add in the legendaries, but all of the pricey cards featured in this deck have been meta-defining and will continue to bring value to your collection.
However, for each mulligan you take, youll need one extra draw step (one extra turn) in order to get the number of cards you need to win