For a deeper dive, see our guide to buying One Piece cards from Japan
The Five Doctors can find any card with the Doctor creature type, not cards with the word "Doctor" in the name
excavate the top 5 cards of your Deck, you can add 1 excavated Spell/Trap to your hand, also send the remaining cards to the GY
Indeed, many people with serious expertise in statistics believe that pile shuffling is a better option
Look closely at that lovely text: you get a 1/1 dragon token on every upkeep, not just yours
Contents of the set Monster Relinquished N3 Golden-Eyes Idol N2 Millennium-Eyes Illusionist N3 Illusionist Faceless Magician N2 Death Guide to the Demon Development World N3 Sangan N2 Fusion Parasite R2 Radian, the Multidimensional Kaiju N2 Armageddon Knight N1 Magic Preparation of Rites N3 Preparation of Rites N1 Super Polymerization UR1 Polymerization N1 Instant Fusion N1 One Chance