Cards tied to prizes, contests, and promotional events tend to be the scarcest, because they were never meant for mass distribution in the first place
Most of the missions are relatively easy, such as the Daily Missions, which feature an objective that is simply logging on once a day
Max Potion [League] #128a Pokemon Guardians Rising Keep track of your collection value over time
The first ever legendary item printed in Lorcana and a whopping seven cost to play a card which cant be inked should probably give you some indication how strong this item can be in the right deck
As time goes by and Wizards releases new sets, more cards get released that screw around with the Exile mechanic, making imprisonment less than permanent
You could also make it to Day 2 with five wins and three ties, but my deck isnt likely to tie so I didnt consider that path