Shadow Night Black is our resident purple expert, but I’ve been crushed by him enough times that I can offer some useful feedback. Blue is more of my specialty, and the advice from game 1 follows the game 2 advice. Hope this helps!
For mono-purple, teching 2x Stewardess on T2 is popular and powerful, as they produce the most impact and give the best value super early in the game, and can be workered later when they’re less useful. I do this unless I expect to need a lot of other cards from my codex very quickly.
I almost never tech in a card before I’ve built the matching tech building to be able to play it, and in the rare cases where I do, I pay close attention to when I’ll next reshuffle my discard pile into my deck.
Gold is very scarce in the early game, so I care more about the efficiency of my tech choices early on, and more about raw power later in the game when more workers have been hired.
The midgame Purple strategy that I struggle most to deal with uses Temporal Distortion on a Hyperion to pull in another Hyperion, then another Distrotion to that Hyperion to pull in something else (usually a Tricycloid). I’ve yet to win a game against this strategy.
I really like the idea of comboing Warp-Gate Disciple and Now!, but I’ve yet to successfully win a game with it (not that I’ve tried all that many times yet). So, this is pure theorycrafting on my part, but I think getting sustained value out of Disciples and Chronofixers would be a lot easier after an Nebula is in play.
Playing Spectral Aven against Black starter is difficult at best, because of deteriorate. If you want to use the Aven against black, you can try using Spectral Flagbearers (preferably as Scavenger and/or Technician) to screen the Aven from targeting, but beware this doesn’t work against Disease because of Crypt Crawler.
Quince is an extremely powerful hero when backed by lots of gold (and preferably while accompanied by Macciatus), but is genearlly a weak choice for the early game where gold is scarce. Onimaru, despite being super expensive to level, can attack and kill most L1 heroes by himself thanks to frenzy, and he becomes a terror if he does manage to survive to hit level 8 and start spamming The Art of War.
Teching Overeager Cadet and Brave Knight on T2 is not a bad strategy as mono-blue (especially if you haven’t workered Manufactured Truth), but I prefer 2x Overeager Cadet. Diversifying your tech choices does mean having more options, but in the early game I think it’s more important to save gold to quickly hit Tech II for Garrisons, and to midband Onimaru if he kills a hero.
When going Peace, it’s worth building both Garrisons quickly. You will likely end up wasting draw power by playing units while both your deck and discard are empty, but having 2 helps you more quickly (and inexpensively) dig for a desired card, allowing for far greater consistency and responsiveness. Also, if 1 gets destroyed, having a backup is extremely valuable.
It looks like on Game 1 Turn 5 you only teched in 1 card, despite not finishing turn 4 with 10 or more workers, which is not (corrected typo) allowed. I suggest using the Codex Tracking Spreadsheet if possible, as it makes it easier to catch these kinds of mistakes (maybe in conjunction with my output formatter for ease of use). Legality aside, when building a Peace engine, I recommend flooding your deck with lots of low-cost units to fuel Garrison draws and Drill Sergeant runes.