An important element of the franchise's magic is how spells can be improved
As I already mentioned, the deck has a good pumps package, so these upgrades aren't exactly necessary (but if you already have any of them, it might be a good idea to add it to the list)
Overall Polukranos decks should be constructed as most tribal decks would
I wrote about her in my Archetypes You Can Build in an Hour article, but suffice to say, you can get a really consistent build going just by using her ability
In other words, he's happy to cast some learn instants and sorceries to recur creatures repeatedly (that can also learn, in many cases) to go grab Lessons to cast to recur creatures repeatedly
Rebbec, Architect of Ascension In ancient Dominaria, Rebbec was the greatest architect in the entirety of the Thran Empire