Card Choices:
Permafrost: This card is busted. The tempo gain from permafrosting a 5-drop is going to save your life while you durdle around with privileges and wisdom of the elders. Isn't even bad against armory anymore since you can permafrost their rizhan. Look out for infinite hourglass and bore though.
Strategize: Amazing card, great to pitch away extra justice sigils from privilege or unnecessary visions of austerity. Be careful about getting rid of too much power since this is a very power-hungry deck.
Vanquish: Best removal spell in the game.
Visions of Austerity: Only maindeck this card in relic-heavy metas, but when you hit their azhindel's gift, flamestoker, or xenan obelisk it will feel really good. Also deals with the disciplinary weights from teacher of humility in a pinch.
Wanted Poster: If we could fit 4 in the maindeck, we would. Can get stuck in hand at times though, so 2-of is safer. Also useful to pop icaria aegis.
Eilyn's Choice: Sometimes great, sometimes terrible. If you're playing against a good opponent who plays around it, you can fall really far behind in tempo. On the other hand, it does deal with a killer carnosaur or a lethal icaria (with the help of something else). It also counters channel the tempest and rise to the challenge, so if you have this against an armory deck make sure to keep it up.
Hailstorm: Busted.
Jennev Merchant: 3/2 Aegis is a surprisingly resilient body, perfect for blocking aggro units or eating a lethal weapon hit. More importantly, it can ditch your expensive or useless cards for the perfect answer. We'll talk about individual market choices later.
Privilege of Rank: Basically the justice version of wisdom of the elders. This deck is super power-hungry, and you can always ditch extra power to strat or merchant. One downside is your manabase starts to suffer, you will sometimes run out of justice sigils in the lategame, or very rarely not be able to cast channel on 8.
Wisdom of the Elders: Literally the primal version of wisdom of the elders. Ez 2-for-1.
Auric Runehammer: Great when it's good, terrible when it's bad. Add the 4th if you aren't seeing any time midrange. 3-of for now because, although you usually want to draw one, you almost never want 2.
Harsh Rule: Your number 1 way to regain tempo. Not much to say about this, just watch out for stand together.
Throne Warden: Deceptively strong, will often save you from lethal damage. Curving runehammer into warden feels amazing, and it might even be better against aggro than harsh rule. It does kind of blow against time midrange, so if you see a lot of that you might want to cut some/all of these.
Channel the Tempest: Target their units over their face. You have enough win-cons that you don't need to worry about decking, you just need to run them out of cards. Also, don't be afraid to ditch this to your merchant in favor of a hailstorm, drawing 3 cards is nice but staying alive is better.
Sword of the Sky King: The big donger. Great answer to icaria, great win-con against most decks in general. Do your best to keep the sword alive, but sometimes you'll be forced to use it to kill an icaria and a tavrod or something. That's fine, you're still getting a 2-for-1. Also, playing this just to gain 8 life and avoid lethal is a very relevant line.
Powerbase: 27 power because I'd rather play hooru banners than seek power. You need 6 justice sigils minimum for the privileges, and 4 primal waystone are necessary. I think clan standard is the best sigil period, even better than amber waystone, and will help a ton against flood in the lategame. Also, double clan tactic kills icaria. Also also, clan tactic kills relic weapons. The card is insane.
--- Market---
Visions of Austerity: Although you have 2 in the maindeck, you won't always draw them. Best to have one here to guarantee relic hate if you need it, because flamestoker, xenan obelisk, disciplinary weights, and azhindel's gift are really hard for you to beat.
Hailstorm: It sucks to hailstorm away our own merchant, but you still need this against aggro.
Eilyn's choice: A pretty good primal removal spell. Does double-duty as a counter for channel the tempest in the control mirror.
Eilyn, Clan Mother: Your answer to dawnwalker, makto, scourge of frosthome, and most time midrange decks. Mono-time basically can't beat an ultimated eilyn. Don't get it against decks with justice in them though, because the opponent will almost certainly have vanquishes in hand.
Rain of Frogs: Rain of Frogs -> Pick Icaria the Liberator -> Opponent concedes.
Hooru Control, and control decks in general, are never quite finished. You constantly need to be updating your deck and changing cards around to adapt to the metagame. This is my build for a very icaria-heavy and relic-heavy meta. Against a more midrange meta, try taking out the runehammers and probably the throne wardens for some end of the stories (6-cost wrath). In aggro metas, you could try to fit in some lightning strikes and/or lightning storms instead of eilyn's choice. If we had extra room, I'd try to fit in the other 2 wanted posters as well as a third sword of the sky king. The third eilyn's choice, the 4th throne warden, the 4th runehammer, and maybe 1-2 eilyn, clan mothers would be next.
Extra:
Kothon: Decent card, but 8 power for a 4/4 and 2/3 flier isn't great, and playing a unit that dies to torch without getting any value sucks.
Polymorph: Eilyn's choice is going to be better 90% of the time, and the other 10% just get eilyn from the market to silence their dude.
Jotun Feast-Caller: Dies to runehammer, dies to carnosaur, and dies to all the removal our opponent has stuck in hand because we don't play any other important units.
End of the Story: Once you go over 8 wraths (4 harsh rule 4 hailstorm), they start becoming really expensive slays. Also, gets blown out by stand together really bad. You'll never get to trigger the tribute, so just ignore that part.
Eilyn, Clan Mother: Dies to vanquish. Get the copy in the market if you need it.
Scourge of Frosthome: This card is just way too expensive for what it does. I'd rather just play channel the tempest. If your opponent has any way to silence it or any way to kill it without a spell (eilyn, clan mother and sword of the sky king for example) it does nothing.