As a land, it can't be countered, and it offers permanent card draw potential, even if you have to discard three cards after drawing just two
Youll want your deck to have ways to put lands in the graveyard, be it fetch lands, cards like Harrow, or self-mill like Malevolent Rumble
They had no idea that worlds beyond their own, such as Amonkhet, even existed
Id avoid some retailers that sell them at full price (or more!) and instead look for places selling these 12-card packs at a discount
Besides the obvious combo deck with Saheeli Rai, which looks to be just as good as you think it may be, Felidar Guardian may also be a welcome addition to a Panharmonicon deck
This set features unique references to old designs (check out the similarities between Secret Identity and Unmask in the artwork) as well as amusing memes with the printing of Impostor Syndrome