There are four available for Final Fantasy: Revival Trance (Final Fantasy 6), Limit Break (Final Fantasy 7), Counter Blitz (Final Fantasy 10), and Scions and Spellcraft (Final Fantasy 14)
Planeswalkers (18) 2 Karn, Scion of Urza 1 Teferi, Hero of Dominaria 4 Teferi, Time Raveler 3 Saheeli, Sublime Artificer 4 Narset, Parter of Veils 4 Sarkhan the Masterless Lands (25) Spells (17) Sideboard Planeswalkers (19) 4 Teferi, Hero of Dominaria 2 Dovin, Hand of Control 1 Liliana, Dreadhorde General 4 Teferi, Time Raveler 3 Kasmina, Enigmatic Mentor 4 Narset, Parter of Veils 1 Ugin, the Ineffable Lands (25) Spells (16) Players wont end up at the same place, though, at least not at first
It's not as effective as its inspiration, actual Eternal Witness, but Witness rarely contributes to combat
This is to help fight against absurd life gain strategies, as well as just allowing for some entertaining deck designs
Regardless of which way you decide to take the deck, filling it with Snow cards is the way to go