I just recently bought this to get back into mtg. Going to play it out of the box for a little bit and upgrade it slowly. Thank you for the blueprint video.
I did the same thing with the Counter Surge deck when the first batch of challenger decks were released. It was nice having the extra Walking Ballistas and Fatal Pushes. :)
Sorry it took so long to respond! I've had covid and fell behind on comments. The reason Spirits decks will play Brazen Borrower is because it's a great tempo card. Tribal spirits are very tempo-y by nature, and Borrower is one of the better blue tempo cards ever printed, so some people will run it even though it's not a spirit. :)