-Drop rate: more or less once every 50 days
-Other drops:
--Equus in amounts (50, 100, 150, 200)
--Apple seeds in amounts (15, 20, 30, 35, 40, 45)
--assortment of 2** tack
--Oats in amounts (50, 100, 150)
--Flax in amounts (10, 15)
--APs in amounts (5, 10)

*there may be additional amounts of the above drops available, with the exception of 1× magic hate*

-Cost:
--> At least 10-13mil equus in the direct flash sales (NB: prices in the direct flash sales fluctuate, therefore the above stated price may not be completely accurate.)
OR
-->AT LEAST 1million equus in the auction flash sales
OR
-->× amount of passes that is used to complete your card collection. Remember, the cards that you buy are random so whether you get the card that you are looking for is up to luck. Unless you buy and use a pack of jokers which costs 495 passes per pack for 3 jokers (with a silver and a bronze joker guaranteed). The normal pack of 4 cards costs 95 passes per pack with at least 2 bronze cards each and a diamond card guaranteed IF you don't find one after buying 5 packs.

-Try to collect all your daily cards every day. You can get 2 cards from logging in, 1 card from taking a horse on a ride and 1 card for winning a competition.

-If you log in for 5 days in a row, you get an extra card upon log in on the 5th day. If you miss a day, then you lose your log in streak and it is reset to day 1. If you want to get max. free cards from the promo, log in daily and do rides and comps with your horses.

-You can trade 1 card per day.
Cost of trading cards:
-->Diamond cards: 100 000eq to trade
-->Gold cards: 50 000eq to trade.
-->Silver cards: 20 000eq to trade.
-->Bronze cards: 5 000eq to trade.

-Trade out each duplicate card that you get as you get them to complete your collections. You want to prevent the duplicates from piling up before you complete your collections (if you want to complete your collections). Because you are limited to 1 trade per day, it can be very difficult to switch out unwanted/useless duplicates towards the end of the event. So try to minimize the number of unwanted duplicate cards in your deck by trading them out as you get them. BUT, duplicates can also be used to complete collections multiple times so you need to be careful about which ones you trade.

-You lose the ability to trade cards of a certain rarity after you have collected all the cards from that rarity. Eg after you collect 1 of every bronze card in the event, you will no longer be able to trade bronze cards out for different bronze cards. This is because trading is supposed to be used to switch out cards that you already have for cards that you do not have. So if you already have all the possible cards for a certain rarity you will no longer be able to receive cards that you do not have. Hence, you will no longer be able to trade for them.

-Validate all the cards that you don't have yet immediately, but keep your jokers until the last day. The jokers can be used as a stand-in card for another card in a collection (if you don't have a card in a certain collection and you want to complete a collection) or it can be used as a prize card. To get the most use out of your jokers, you may want to wait until the end of the event when you know what cards you have and don't have in your collections/prize pool.

-You can use a diamond joker to get yourself a divine named Etrian. Or you could use it to get yourself any other diamond collectable in the event.

Card sales:
-(Taken directly from the "Get more cards!" page):
"Each pack contains 2 bronze cards (amongst which at least one of the cards you don't have yet) and2 rarer cards! If you open 5 packs without finding a diamond card, you're guaranteed to find one in the next pack.

Make the most of it, it's the moment to complete your collection!

Please note that if you already have all the bronze cards, it may be the case that a pack doesn't contain any cards you are missing."
NB: It costs 95 passes for 4 cards during this offer.

-Taken from the "Get more joker cards!" page:
NB: It costs 495 passes for a pack of 3 jokers.
". Each pack contains:

1 bronze joker card
1 silver joker card
1 uncommon joker card"

-There are 2 ways to win the ultimate prize/divine:
1) You could complete all your collections to unlock it or
2) You could buy it in the flash sales. However, this will cost a TON of equus. (See further below)

-You can complete the same collection multiple times (and win the prize that the collection offers multiple times) if you gather each card in the collection multiple times. This means that your duplicate cards may come in handy if you have several duplicates in the same collection.

-You can complete the promo several times over and win the ultimate divine over and over again. E.g if you complete each collection twice, you can win 2×Kawaii.

-This is a very expensive event. If you don't have a lot of equus/passes, you probably won't be able to complete the event unless your luck with your daily cards (especially towards the end of the event) is exceptional and you don't have to waste equus/passes trading your cards out/buying card packs in attempt to get cards that you don't have yet.

-If you don't have much equus, then try to avoid participating in the flash sales. It would probably be better for you to save your equus for trading your cards later in the promo because then at least you'll get a card that you don't have. If you use your equus in the flash sales, then the card that you bought may end up being a card that you already have and you may not have enough equus to trade it out for something that could potentially be better.

-Try to gather as much equus as possible to spend in the flash sales (..if you are going to participate in the flash sales). Everything in the flash sales is very expensive.

-The flash sales can also be very frustrating if you buy the wrong card. REMEMBER: you can only buy 1 card per sale every 2 days, so you need to make sure that when you click bid/buy, you are clicking on the card that you actually want. Not the card that's under/above it.

-If you're going to participate in the flash sales, then try to get a fast and stable internet connection beforehand. The last thing you want to do is to bid on a card that you want and then click refresh, only to find that you have already been outbid and have lost the auction due to slow internet connection. Or to see a diamond card in the direct flash sales but then have it disappear so quickly that you didn't even see it appear on the list of cards to buy because someone else has a better connection and bought the card before you even had the chance to do so. Fast internet connection is a must-have if you want to participate in the flash sales.

-Every time you buy a card from the flash sales, you partially fill the meter at the top of your screen. (I'm referring to the meter on the flash sales page.) The fraction by which you fill the meter increases with the rarity of the card that you bought (bronze cards fill the meter a bit, silver cards fill the meter more than bronze cards, gold more than silver and diamond more than gold. Oh yes, and buying Kawaii from the sales fills you meter more than diamond cards.) If you reach the given marks on the meter, you can unlock jokers of each card rarity in ascending order. Once unlocked, you can then purchase the jokers with equus whenever you want (if you want to do so). [spoiler][/spoiler]

In the direct sales:
-Kawaii costs 10-13 mil eq.
-Diamond cards cost 1.1-1.2 mil eq each.
-Gold cards cost 75-110K eq each.
-Silver cards cost 40-52K eq each.
-Bronze cards cost 15-20K eq each.
NB: prices in the direct flash sales decline over time.
.•. 1) the above prices may not reflect the full price range for each card
2) it's cheaper to wait before you buy cards from the promo
(Thanks for clarifying this @AdmYrrek!

In the auctions:
-The minimum bid for the Kawaii is 1 000 001eq.
-The minimum bid for Diamond cards is 30 001eq.
-The minimum bid for Gold cards is 20 001eq.
-The minimum bid for silver cards is 10 001eq.
-The minimum bid for Bronze cards is 5001eq.

*NB: Just because the MINIMUM prices in the auctions are much cheaper than in the direct sales does NOT mean that the cards will sell for cheaper. The direct sales is often times cheaper than the auctions. I have seen bronze cards sell for over 50K equus in the auctions in previous events. BUT, I have also seen gold cards sell for their min. price.
Be careful with how you use your equus in the flash sales. It can be very easy to lose your whole reserve in a bidding war or by buying expensive cards in the direct sales, especially if you're trying to get a higher rarity card that may end up being a duplicate of one of the cards that you already have because then you may still need to pay another fortune to trade it out*

Cost of the Jokers that you can unlock by buying cards in the flash sales:
-The Diamond joker: 2,366,400eq.
-The Gold Joker: 180 960eq.
-The Silver Joker : 87 000eq.
-The Bronze Joker: 29 000eq.
NB: Buying these joker cards will not count towards filling your joker meter.

-Also, you the joker meter disappears after you fill it the first time, therefore you cannot fill it more than once.