Printable proxies
⬇ Download the print-ready proxy PDF — 9-up US Letter, 300 dpi, cut guides. Print at 100% / actual size.
At a glance
- Format: cEDH (Commander)
- Commander: Thassa, Deep-Dwelling
- Colors: Blue (U)
- Archetype: Mono-blue blink control / ETB value with a compact combo finish
- Power tier: high-power (bracket 4)
Strategy
Thassa, Deep-Dwelling — Mono-U Blink Control (Bracket 4)
The core idea: treat Thassa as a permanent, not a creature. She is indestructible either way, but while your devotion to blue is under five she isn’t a creature at all — which dodges the things indestructible does NOT stop: Toxic Deluge and other -X/-X effects, edicts, “exile target creature”, and creature theft. Opponents cannot raise your devotion, so it is a dial you control. That is why all seven mana rocks are colourless artifacts with zero blue pips, and why this deck deliberately runs no Nykthos and no devotion payoffs — they would fight its own protection.
The engine. Her end-step trigger is free, unconditional and repeatable, and it works whether or not she is currently a creature. 25 creatures, ~20 with a relevant ETB: repeatable removal (Duplicant exiles a creature and the exile does NOT return when Duplicant is blinked; Meteor Golem is a repeatable Vindicate; Man-o’-War and Aether Channeler bounce), repeatable theft (Agent of Treachery and Sower of Temptation stay stolen, because Thassa returns the blinked creature under your control), repeatable tutors (Spellseeker, Trinket Mage, Tribute Mage), counters on a stick (Tishana’s Tidebinder, Venser, Torrential Gearhulk) and regrowth (Archaeomancer, Mnemonic Wall). Panharmonicon doubles the ETB of whatever gets blinked — note it does NOT double the blink itself, which triggers at the beginning of your end step rather than on something entering.
Why the removal is body-shaped. Mono-blue has no real removal, so the deck buys it on creatures that Thassa re-fires every turn for free. From about turn six, most turns strip a real permanent off the table for zero mana.
Sweepers that don’t hit you. Curse of the Swine exiles target creatures and Evacuation returns all creatures — at devotion under five Thassa is not a legal target and does not bounce, and your own ETB crew returning to hand is a refuel rather than a loss.
Play notes. Displacer Kitten returns a blinked permanent under its OWNER’s control — never point it at something stolen with Agent of Treachery; Thassa’s own trigger has no such problem. Eight 2-pip permanents are in the list, so Thassa plus any two of them plus one more pip flips her into a 6/5 creature — usually you only want that when you need a blocker.
Cards
Decklist
Paste straight into MTG Arena (or Moxfield/Archidekt):
Commander
1 Thassa, Deep-Dwelling
Deck
28 Island
1 Ancient Tomb
1 Urza's Saga
1 Otawara, Soaring City
1 Minamo, School at Water's Edge
1 Riptide Laboratory
1 Mystic Sanctuary
1 Academy Ruins
1 Tolaria West
1 Sea Gate Restoration
1 Sol Ring
1 Mana Vault
1 Grim Monolith
1 Arcane Signet
1 Mind Stone
1 Chrome Mox
1 Lotus Petal
1 Sensei's Divining Top
1 Isochron Scepter
1 Panharmonicon
1 Thassa's Oracle
1 Snapcaster Mage
1 Aether Channeler
1 Man-o'-War
1 Spellseeker
1 Trinket Mage
1 Tribute Mage
1 Tishana's Tidebinder
1 Gilded Drake
1 Venser, Shaper Savant
1 Sower of Temptation
1 Subtlety
1 Archaeomancer
1 Mnemonic Wall
1 Spark Double
1 Displacer Kitten
1 Mulldrifter
1 Peregrine Drake
1 Solemn Simulacrum
1 Deadeye Navigator
1 Torrential Gearhulk
1 Agent of Treachery
1 Duplicant
1 Meteor Golem
1 Walking Ballista
1 Force of Will
1 Force of Negation
1 Fierce Guardianship
1 Mana Drain
1 Counterspell
1 Swan Song
1 An Offer You Can't Refuse
1 Muddle the Mixture
1 Mystic Confluence
1 Cryptic Command
1 Pongify
1 Rapid Hybridization
1 Into the Flood Maw
1 Cyclonic Rift
1 Curse of the Swine
1 Evacuation
1 Rhystic Study
1 Mystic Remora
1 Propaganda
1 Ponder
1 Preordain
1 Fact or Fiction
1 Mystical Tutor
1 Merchant Scroll
1 Blue Sun's Zenith
1 Ghostly Flicker
1 Dramatic Reversal
Card images & data via Scryfall.