Your list looks sweet! The two biggest things that are missing in my opinion are Jace the Mind Sculptor, which goes very well with Temporal Mastery and Terminus, and Part the Waterveil, which allows you to kill much faster than any other wincon currently in the deck. I have some nitpicks about card choices, but a lot of this is personal preference, so take everything with a grain of salt. Remand is weak in the format right now in my opinion because the top decks have very few spells that are good Remand targets. For example, Phoenix is mostly cantrips, so Thing in the Ice, Pyromancer Ascension, and Manamorphose are the few cards you can Remand and feel like you've accomplished something, and all of those come down before Remand when you're on the draw; Humans and Spirits have Cavern of Souls and Aether Vial that make Remand a very poor cantrip; Dredge has basically Cathartic Reunion and Conflagrate as the only spells that Remand is good against. Nexus of Fate in my experience is mostly an un-Miracleable Temporal Mastery. The Instant speed is rarely relevant because we beat counterspells by Gigadrowsing at the opponent's end step, and the shuffle clause is rarely relevant. It doesn't stop you from decking if you have a Mine or two out, and increasing the extra turn density of your deck is rarely the difference between winning and losing. Your Planeswalkers are in my opinion all outclassed by Jace the Mind Sculptor, in part because of the 5 Miracle cards in the deck. Manlands like Celestial Colonnade I've often found to be too slow, and I also don't like having more than one always-tapped land (you have both Colonnade and Temple of Enlightenment). I'm not a fan of basic Plains or Field of Ruin in the deck because of how important blue mana is for Gigadrowse, but I can see how that package goes together. I don't like the Laboratory Maniac sideboard plan, since I think it's rare than you can win with it in games 2 and 3 when your opponent has more interaction, like Naturalize eff
ects for your Mines, or Thoughtseize effects, or counterspells. Like I said, these are just my personal opinions, so feel free to make as many or as few changes as you want. For example, Remand is great in certain metas full of decks like Tron, UW Control, and BG, so if your local store has tons of decks like that, then it's a fantastic inclusion.
I know many players are excited about Kefnet, but I've been mostly impressed by Narset, Parter of Veils 1UU. She can practically brake the symmetry of ours Mines and Edicts, plus she gives us 2 ticks down of Azcanta.
How does a card like that work with cryptic command exactly? As in: if you cast a spell and your opponent casts a cryptic with the modes "counter target spell & draw a card" can you change the modes with the copy to be like "bounce target permanent and draw a card"?
As for it's place in Taking Turns, I could see it being played in the more turbo fog styled decks that run more at instant speed. I may be wrong.
Lots of cards from this set are going to need testing
You cannot change the mode chosen by the opponent ( same happens with commandeer ), you can change the target of the modes, if there is no legal target in either one of the two modes, the spell will just fizzle.
I know many players are excited about Kefnet, but I've been mostly impressed by Narset, Parter of Veils 1UU. She can practically brake the symmetry of ours Mines and Edicts, plus she gives us 2 ticks down of Azcanta.
You cannot change the mode chosen by the opponent ( same happens with commandeer ), you can change the target of the modes, if there is no legal target in either one of the two modes, the spell will just fizzle.