I take it aggro isn't a thing in your meta? Your deck is very slow. Just checking since you don't have much going on in the early game.
If you're playing Blue then you might want to run Recurring Insight over The Immortal Sun since it's faster and have better synergy with the Wall and Nezahal. Your doesn't doesn't have any tutors and such so you can't exactly find it when needed.
I wouldn't run 4 Denials and would like to see at least 1 Spell Burst. I might cut a couple of them and/or a land for some Thought Vessels so that you have more turn 2 plays. Turn 2 pass always feels lame. Mind Stone could work too but I don't think that "running out of cards" will be a concern for this deck so I'd rather have the bigger hand size.
I almost always try to sneak in a Parallax Tide when I have Sowers in my Blue decks. It's so satisfying :). It might not be good but it's fun for... most people.
Hmmm - what does a blue mage do to protect himself against a rush? The fourth wave? That starfish 2 drop?
Depends how fast your meta is. I like 6-8 2 drops, 6-8 3 drops and at least 4 powerful 4 drops. For your deck I'd probably cut the Starfishes for the full 4x SGO because both it and Whelming Wave are solid spells to cast on turn 3. It's not a big change but adding another 3 and another 4 can make-or-break your early game insofar as you draw them. That being said I kinda just realized that you're playing Post so Whelming Wave probably isn't the spell for you. What about Coastal Breach? It's usually strictly better anyways.
4 Glimmerpost
15 Island
1 Eye of Ugin
4 Sapphire Medallion
1 Crystal Shard
1 The Immortal Sun
3 Mnemonic Wall
4 Oblivion Sower
3 Nezahal, Primal Tide
2 Ulamog, the Ceaseless Hunger
4 Arcane Denial
4 Manifold Insights
3 Whelming Wave
The idea is to generate infinite value!
If you're playing Blue then you might want to run Recurring Insight over The Immortal Sun since it's faster and have better synergy with the Wall and Nezahal. Your doesn't doesn't have any tutors and such so you can't exactly find it when needed.
I wouldn't run 4 Denials and would like to see at least 1 Spell Burst. I might cut a couple of them and/or a land for some Thought Vessels so that you have more turn 2 plays. Turn 2 pass always feels lame. Mind Stone could work too but I don't think that "running out of cards" will be a concern for this deck so I'd rather have the bigger hand size.
I almost always try to sneak in a Parallax Tide when I have Sowers in my Blue decks. It's so satisfying :). It might not be good but it's fun for... most people.
Guilds of Ravnica - Commander 2018 - Core 2019 - Battlebond - Dominaria - Rivals of Ixalan - Ixalan - Commander 2017 - Hour of Devastation - Amonket - Aether Revolt - Commander 2016 - Kaladesh - Conspiracy 2 - Eldritch Moon - Shadows Over Innistrad - Oath of the Gatewatch - Commander 2015 - Battle for Zendikar - Magic Origins - Dragons of Tarkir
Green - Blue - Red - White - Gold
Varying up the counter suite seems decent - Swan Song, Spell Burst, Supreme Will, and Arcane Denial.
And then perhaps Expropriate for the top end?
1 Swan Song
1 Spell Burst
1 Arcane Denial
1 Supreme Will
4 Manifold Insights
4 Whelming Wave
1 Recurring Insight
1 Expropriate
4 Sapphire Medallion
2 Sigiled Starfish
2 Sea Gate Oracle
3 Mnemonic Wall
3 Oblivion Sower
3 Nezahal, Primal Tide
1 Ulamog, the Ceaseless Hunger
4 Glimmerpost
13 Island
1 Eye of Ugin
Depends how fast your meta is. I like 6-8 2 drops, 6-8 3 drops and at least 4 powerful 4 drops. For your deck I'd probably cut the Starfishes for the full 4x SGO because both it and Whelming Wave are solid spells to cast on turn 3. It's not a big change but adding another 3 and another 4 can make-or-break your early game insofar as you draw them. That being said I kinda just realized that you're playing Post so Whelming Wave probably isn't the spell for you. What about Coastal Breach? It's usually strictly better anyways.
Guilds of Ravnica - Commander 2018 - Core 2019 - Battlebond - Dominaria - Rivals of Ixalan - Ixalan - Commander 2017 - Hour of Devastation - Amonket - Aether Revolt - Commander 2016 - Kaladesh - Conspiracy 2 - Eldritch Moon - Shadows Over Innistrad - Oath of the Gatewatch - Commander 2015 - Battle for Zendikar - Magic Origins - Dragons of Tarkir
Green - Blue - Red - White - Gold
^ good list. Nothing beats going infinite with Clone Legion + Mnemonic Wall :).
Guilds of Ravnica - Commander 2018 - Core 2019 - Battlebond - Dominaria - Rivals of Ixalan - Ixalan - Commander 2017 - Hour of Devastation - Amonket - Aether Revolt - Commander 2016 - Kaladesh - Conspiracy 2 - Eldritch Moon - Shadows Over Innistrad - Oath of the Gatewatch - Commander 2015 - Battle for Zendikar - Magic Origins - Dragons of Tarkir
Green - Blue - Red - White - Gold