I’m not a MtG player(at least I haven’t been for several years), but I thought a lot of the cards I’ve seen from the Tarkir block on the Internet have been quite interesting. Nice mix of multicolored cards and cool tribal synergies that would make for some neat deck building opportunities.
Mindslaver. Exile all their cards in hand, waste loyalty and removal on their own creatures (if possible). Though im pretty sure itd cause game freezes like crazy if it were somehow implemented.
Mirrodin, Kamigawa, and Time Spiral were my favorite blocks. I seriously love the depth of lore in MTG and how the cards tell the story of the block in some way. And who can NOT love the Harmless Offering card in Eldritch Moon?