Into the Depths
The newest Speed Duel set, Trials of the Kingdom, added support to many current decks as well as unique, strategy-defining skills. My favorite deck to surface from the new card pool revolves around a new skill card, Terror from the Deep! and a monster card never printed before in the TCG, Kairyu-Shin.
Kairyu-Shin is a level 5 normal Sea Serpent monster with 1800 attack and 1500 defense. Although the first TCG printing of Kairyu-Shin came in Trials of the Kingdom, the OCG has had several printings since 1999. Believe it or not, there are still many cards missing from the TCG cardpool that are older than the TCG itself. Konami probably didn’t think that introducing normal monsters in core sets made much sense. But in Speed Duels, these cards be printed with strategies in mind. 
This brings us to the newest Mako Tsunami (or Ryota Kajiki) skill, Terror from the Deep! This skill reads “Activate this Skill during your Main Phase, while you control "Kairyu-Shin". When this Skill is activated, you can activate "Umi" directly from your hand, Deck or GY. While you control "Kairyu-Shin", all WATER monsters you control are unaffected by Trap effects. If "Kairyu-Shin" you control leaves the field, draw two cards, and if you do, flip this card over.”
With Terror from the Deep in mind, I put together a decklist to turbo out Kairyu-Shin as quickly as possible to activate the skill.
Swabbing the Decklist
Monsters
3x Kairyu Shin-The mascot of the deck and the reason to play the skill card. Trap protection is pretty great in Speed Duels with only so many cards available to interrupt your plays. If your opponent can not use traps against you, that is one less thing to worry about.
2x High Tide Gyojin-A big beatstick is all you need sometimes in Speed Duels, especially if your opponent can’t activate trap cards. Its 1650 attack is great and boosted with Umi to 1850, where not many normal summons can compete.
3x Levia-Dragon-Daedalus- Levia Sends Umi to the GY to destroy all other cards on the field. Board wipes are great in general, but in Speed Duels can outright win you the game.
3x Slushy- Revives your level 5 or higher Sea Serpents from the GY if you have three or more copies in the GY or banished.
3x Sphere Kuriboh- One of the best cards in speed duels, Sphere Kuriboh gives you more time to draw into your combo pieces
Spells
3x Cost Down- Lets you summon Kairyu-Shin without tribute for only a discard (preferably Slushy). Easiest way to get Kairyu Shin on field.
3x Big Wave Small Wave-Lets you special summon Kairyu-Shin or Levia by destroying water monsters. Slushy is better in the GY and High Tide Gyojin is a noble sacrifice for your win condition.
1x Umi- The skill activates Umi from deck, GY or hand so no matter where it is we can find it. It gives our monsters a 200 Atk/Def boost. You can use Levia to send Umi to grave to blow up the field triggering your skill to draw two cards by destroying Kairyu-Shin.
Swimming Lessons
A Good Play
Cards in Hand: Kairyu-Shin, Cost Down and any other card.
1- Activate Cost down, discard other any card in hand except Kairyu-Shin, preferably Slushy.
2- Normal Summon Kairyu-Shin.
3-Activate Skill Terror from the Deep! which activates Umi from Deck and protects water monsters from trap effects when Kairyu-Shin is on the field.
The Best Play
Starting Hand-Cost Down, Big Wave Small Wave, Levia, Kairyu-Shin, Anything else (Going Second)
1-Activate Cost Down, discarding unimportant card.
2-Normal Summon Kairyu-Shin.
3-Activate Skill, activating Umi from deck and protecting Water monsters from trap effects.
4-Activate Big Wave Small Wave, destroying Kairyu-Shin to special summon Levia.
5-Skill activates to draw two because Kairyu-Shin was destroyed.
6-Levia effect to send Umi to destroy all cards on the field.
The Game-Winning Play
What you need: Three Slushy in Grave, Kairyu-Shin and Umi on field, Big Wave Small Wave (or Cost Down if you have one other card in hand) and Levia in hand.
1-Activate Big Wave Small Wave, sending Kairyu-Shin to the GY to special summon Levia (or use Cost Down discarding one other card in hand to tribute Kairyu-Shin to summon Levia).
2-Draw two cards because Kairyu-Shin was sent from field to the GY.
3-Use Levia's effect to send Umi to the GY to destroy all cards on field.
4-Use Slushy effect, banishing one copy to special summon Kairyu-Shin from the GY.
5-Now you can activate Terror from the Deep, activating Umi from the Grave.
6-Then, attack for over 4000 damage, winning the game.
There are Bigger Fish to Fry
This is my current build for the deck and I hope it helps you sea success. But I am always adjusting for changing tides! What cards can you see being released to make this deck better? Which puns did I miss out on? Let minnow what you think!
