My umi Recipe (Genesys)

Umi Guide

I've been playing this deck for the last few years, and day by day, I'm trying to make it more consistent and solid. It's not based on a main strategy — it's more of a "do your best with what you have" kind of deck. So it’s really about knowing the deck deeply and thinking carefully about your options. That’s why I love it.

We’re a go-first deck. Our main control monsters are, of course, Electric Jellyfish and Ocean Dragon Lord – Kairyu-Shin, used to control the field and block your opponent’s summons. If you have both in hand, you usually go for Jellyfish to send A Legendary Ocean to the GY, and then summon Kairyu-Shin. From here, you have several options depending on your hand and your strategy. You should activate Kairyu-Shin’s effect and choose between:

- Another A Legendary Ocean (not ideal, in my opinion)

- Sea Stealth II, which gives you "Umi with steroids"

- Sea Stealth Attack (my favorite option), which lets you bring back the A Legendary Ocean you sent to the GY earlier without wasting resources, and gives you two bonus effects — saving one of your monsters and offering removal during the Battle Phase. It's also a great surprise for your opponent, who might see their board vanish after setting it up.

- Kairyu-Shin’s Dark Reef — only go for this if you potentially have more than one "Umi" on the field or if you already have Sea Stealth Attack. If you activate both in a chain (preferably Dark Reef first), you can send A Legendary Ocean to the GY and recover it with Sea Stealth Attack.

Abyss Shark is another key monster in the deck because it allows us to search for other sharks. Again, your choice depends on the situation. The two best targets are N.As.H. Knight and Number 4: Stealth Kragen. Both Crystal Shark and Dream Shark are good for this, but be very careful:

With Crystal Shark, you can go for either Rank 5 (N.As.H.) or Rank 4 (Kragen) since Crystal and Abyss give you flexibility. However, Crystal locks you into only Xyz Summons for the rest of the turn.

Dream Shark can only go for Rank 5 (or Rank 4 if you have A Legendary Ocean on the field). So plan accordingly before choosing which shark to play.

Final tip on sharks: Crystal Shark is a great option if you already have Number 4: Stealth Kragen on the field, since you can halve an opponent’s monster’s ATK and then summon Crystal Shark for free. 

Icejade Ran Aegirine is a good shortcut to Synchro Summons. Like Dream Shark, keep A Legendary Ocean in mind and decide beforehand whether you want to go for a Level 10 or Level 8 Synchro. Crystal Shark is also a solid option here since its GY revival effect can come in handy.

Lappis Dragon... my dear friend. I think I’m the only person in the world who plays this guy in their deck. This bro has given me the greatest joys — and the biggest headaches. It can be a game-changer or the reason for your defeat. But seriously, it’s surprisingly useful thanks to its ability to be summoned when added to your hand — whether from the deck or GY. This works especially well with Ice Barrier, which adds monsters from the GY, giving you a surprise 2600 (potentially 2800) ATK body during the Battle Phase.

Fish Sonar is basically your searcher for Electric Jellyfish or Kairyu-Shin.

Sea Stealth II is especially useful with Sea Stealth Attack — you can "revive" a monster from the GY or special summon one at the End Phase. You summon a monster from your hand or GY using Sea Stealth II, then banish it with Sea Stealth Attack to bring it back at the End Phase.

The Extra Deck is quite simple and straightforward. There's not much to explain — the monsters do different things, and sometimes it’s not even worth going into them. Remember, this is a control deck, so you won’t be doing long combos. Often it’s not necessary, since Ocean Dragon Lord - Kairyu-Shin can handle things on his own — especially in today's Yu-Gi-Oh!, where WATER monsters are barely in the meta, so no one can summon anything under his floodgate.

Hope this guide helps you get more comfortable playing the deck! Feel free to ask for help or leave suggestions in the comments!