Here is the full list of all 19 Knightfall: Rivals achievements.
Play the game for 30 days.
Upgrade your cards 300 times.
Open 100 total chests.
Win 50 total battles in either Casual Battles.
Win 50 total battles in either Ranked Battles.
Win 10 total battles in either Ranked Battles.
Open 30 total chests.
Play the game for 5 days.
Upgrade your cards 50 times.
Unlock 50 total cards in your collection.
Open 15 total chests.
Win 10 total battles in either Casual Battles.
Unlock 20 total cards in your collection.
Complete the tutorial.
Upgrade your cards 10 times.
Win 300 total battles in either Casual Battles.
Win 300 total battles in either Ranked Battles.
Unlock 300 total cards in your collection.
Play the game for 90 days.