MTG Eluge, the Shoreless Sea Deck by Anrael

Eluge's power and toughness are each equal to the number of Islands you control. Whenever Eluge enters or attacks, put a flood counter on target land. It's an Island in addition to its other types for as long as it has a flood counter on it. The first instant or sorcery spell you cast each turn costs {U} (or {1}) less to cast for each land you control with a flood counter on it.

Flash Flying Whenever Malcolm deals combat damage to a player, put a chorus counter on it. Draw a card, then discard a card. If there are four or more chorus counters on Malcolm, you may cast the discarded card without paying its mana cost.

When Kiora enters, draw two cards, then discard two cards. Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Flying Haughty Djinn's power is equal to the number of instant and sorcery cards in your graveyard. Instant and sorcery spells you cast cost {1} less to cast.

Impending 4—{1}{U}{U} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.) Flying Whenever this permanent enters or attacks, draw two cards, then discard a card.

Flying When this creature enters, return up to two other target nonland permanents to their owners' hands.

This spell costs {1} less to cast for each instant and sorcery card in your graveyard. Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Flash This spell costs {1} less to cast for each instant and sorcery card in your graveyard. This creature enters tapped if it's not your turn. When this creature enters, tap up to two target creatures.

Return target creature or Vehicle to its owner's hand.

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.) Return target creature an opponent controls to its owner's hand. If the gift was promised, instead return target nonland permanent an opponent controls to its owner's hand.

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it.

Spree (Choose one or more additional costs.) + {3} — Create a 2/2 white Spirit creature token with flying. + {1} — Counter target spell unless its controller pays {2}.

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Counter target noncreature spell unless its controller pays {2}.

Spree (Choose one or more additional costs.) + {1}{U} — Counter target spell. + {3} — Create a token that's a copy of target artifact or creature you control. + {2} — Draw two cards, then discard a card.

Counter target spell with mana value 4 or greater.

Tiered (Choose one additional cost.) • Blizzard — {0} — Return target creature to its owner's hand. • Blizzara — {2} — Target creature's owner puts it on their choice of the top or bottom of their library. • Blizzaga — {5}{U} — Target creature's owner shuffles it into their library.

Look at the top three cards of your library. Put one of those cards into your hand, one into your graveyard, and one on the bottom of your library.

Counter target noncreature spell.

Counter target artifact or creature spell unless its controller pays {4}.

Counter target spell unless its controller pays {2} plus an additional {1} for each Faerie you control.

Choose one — • Counter target creature or enchantment spell. • Return one or two target creatures and/or enchantments you own to your hand.

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.) Counter target creature spell. If the gift was promised, instead counter target spell.

This spell costs {U} less to cast if an opponent cast two or more spells this turn. Counter target spell.

Choose one — • Counter target spell. • Surveil 2, then draw two cards. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Draw a card for each Island you control, then discard two cards.

This spell costs {3} less to cast if it targets a permanent you control. Return up to two target nonland permanents to their owners' hands.

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Draw two cards. Then discard a card unless you attacked this turn.

Gain control of target creature with mana value X or less. If X is 5 or more, create a token that's a copy of that creature.

Look at the top five cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Return all nonland permanents target player controls to their owner's hand.

Choose up to five {P} worth of modes. You may choose the same mode more than once. {P} — Draw a card. {P}{P} — Choose an artifact or creature you control. Create a token that's a copy of it. {P}{P}{P} — Return each nonland, nontoken permanent to its owner's hand.

Whenever you draw a card, put a loyalty counter on Teferi. 0: Draw a card. −2: Create a 2/2 blue Spirit creature token with vigilance and "Whenever you draw a card, put a +1/+1 counter on this token." −12: Target opponent chooses a permanent they control and returns it to its owner's hand. Then they shuffle each nonland permanent they control into its owner's library.

({T}: Add {U}.)

As this land enters, choose a creature type. {T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

{T}: Add {C}. {2}, {T}, Sacrifice a token: Draw a card. {3}, {T}, Pay 1 life: Create a 1/1 blue Fish creature token. {4}, {T}: Create a Treasure token.

{T}: Add {C}. {4}: This land becomes a 3/3 creature with vigilance and all creature types. It's still a land.