I wouldnt get excited by a 4-mana draw-three normally, but you dont need to worry about casting the cards until next turn, and getting a burst of free cards gives you enough of an advantage to push a close game in your favor
This is because Zvi Mowshowitz (who has broken more engine cards than any other player in Magic history) built a deck around the Bargain that was so degenerate it was preemptively banned in Extended
The Skysovereign in particular jumps out as something with immediate impact, low mana cost, and huge board presence
They do work well for double sleeving, and the looseness is less of an issue when there's an inner sleeve taking up some of the extra space
As per usual, the cards will be able to be mixed with others from The First Chapter and Rise of the Floodborn , as long as no more than two inks are represented per deck
Baleful Strix I may be a little biased in my love for Baleful Strix but look at this beauty of a card