MTG Mono Blue Aggro Deck by Fruitkid

Exhaust — {X}{U}{U}, {T}: Draw X cards. Put a +1/+1 counter on each Merfolk creature you control. (Activate each exhaust ability only once.)

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) {1}, {T}: Tap target land.

Kicker {1} (You may pay an additional {1} as you cast this spell.) When this creature enters, if it was kicked, target land becomes an Island for as long as this creature remains on the battlefield. This creature gets +1/+1 as long as an opponent controls an Island.

As an additional cost to cast this spell, reveal a Merfolk card from your hand or pay {3}. When this creature enters, draw a card.

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Other Merfolk creatures you control get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Flash When this creature enters, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as this creature remains on the battlefield. (Mana abilities can't be targeted.)

Nonbasic lands are Islands.

Svyelun has indestructible as long as you control at least two other Merfolk. Whenever Svyelun attacks, draw a card. Other Merfolk you control have ward {1}. (Whenever another Merfolk you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

At the beginning of your upkeep, you may put a charge counter on this artifact. {T}: You may put a creature card with mana value equal to the number of charge counters on this artifact from your hand onto the battlefield.

You may sacrifice a nontoken blue creature rather than pay this spell's mana cost. Counter target spell.

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost. Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

({T}: Add {U}.)

{T}: Add {U}. {U}, {T}: Untap target legendary permanent.

{T}: Add {U}. {1}: Return Oboro to its owner's hand.

{T}: Add {U}. Channel — {3}{U}, Discard this card: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

{T}, Pay 1 life: Add {G} or {U}. {1}, {T}, Sacrifice this land: Draw a card.

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}. {1}: This land becomes a 2/2 creature with all creature types until end of turn. It's still a land.