None of these cards are actually required to make this deck work. You can build you own version by keeping these ideas in mind:
You can use WATER monsters to make a beatdown deck by swarming the field and simply relying on their high attack. It's relatively cheap to make since many of them are low rarity or from the card trader. Mako's skill - Mythic Depths is recommended to used in this deck too.
Auto decks are decks that are mainly made to be used with the "Auto-Duel" function. The reason why people often want to go with Auto-Duel is simply because it is done much faster than manual play, since it is fast forwarded and easy to use with just one button. Keep in mind that win rates for auto decks vary depending on what level of Standard Duelists you are going against.
Some decks are made to have a high chance of winning and ends fast. This is good if you ever want to level a character quickly or buy a "Boosted Duel Orb" from the shop. With only an hour of infinite standard duelist spawns, winning the duels quickly can earn you a lot of exp, levelling a character up quite fast.
The other type of decks are made to get a high score with auto duels. These decks might not have a consistently high win rate compared to the ones made to win, but they can often give up to 3000 or 4000 easily by using auto duel from the start. Earning a lot of points from the Duel Assessment will give more rewards like golds, stones/orbs, and most importantly, the standard gate keys and the colored ones used to farm Legendary Duelists.