It's a field designation, so it's amazing that you can use it even if you go first is simply a case where he is sent to GY, so you can use it for various materials, Furthermore, since he doesn't specify which monsters to return to the deck, it is possible to loop with these two cards, as well as hand triggers and key cards
L1 HeartGold & SoulSilver Collection
Until end of turn, lands tapped for mana produce mana of the chosen color instead of any other color
If this card is Normal or Special Summoned: You can excavate the top 3 cards of your Deck, and if you do, you can add 1 excavated "Purrely" Spell/Trap to your hand, also place the rest on the bottom of your Deck in any order
He then told Yuma to not Duel Reginald, but Yuma argued that he had to for himself, not for Bronk
Each time a DIVINE Monster is summoned, Apply 1 of the follwing effects for the rest of the duel.There is no limit to the hand size for each player.Players can gain LP equal to any damage they inflict on their opponent.Once per turn, the Turn Player can tribute 2 Cards from their hand or field, then add to their hand (from their Deck or GY) or Send to their GY (from their hand or Deck) 1 Level 10 or higher monster._