First: As some GM (or other game responsible) once confirmed, the drop rates for monster cards are intentionally reduced (massively) in specific zomes (like silverspring/dust devi canyon). As of my experience it is a massive 50% reduce.
==> This results in almost 1200 kills for the rrequired card drops. (normal zone drops)
==> Again, this takes long time, but eventually also this will be accomplished one day (although i have doubts rregarding "Tatus" monster card and one other^^)
Hello
Drop reduction in Silverspring and Dust Devil Canyon will be removed with todays patch. Tatus card is not effected by server drop rate, due to not being killed by player, but is effected by player drop effects, so would be slightly rarer then other cards due to this.
BUT: The festival cards themselves are far from being farmable.
Some of the festival cards i have never seen, and most are super rare.
This, by itself, may be a good thing.
BUT if you consider, you need 65 of them cards to upgrade to 5 star, this will not be possible in a lifetime I guess^^
In future, we will make some adjustments to festival cards to make it easier to reach 5 stars.
Greetings