I highly suggest giving the game a try for yourself if you haven't already
If you play a 60-card format where it's legal, you can fit Ashiok, Dream Render in a mono-black deck or a mono-blue deck
The White, Blue, and Black (or Esper) deck for Final Fantasy is built around Y'shtola, Night's Blessed, who incentivises you to cast multiple noncreature spells with mana value 3 or greater in a single turn to drain your opponents and draw cards along the way
Beast Within and Generous Gift are popular spells that can be used to deal with a variety of threats
Related Past that, there is a strong token generation and buffing subtheme in the deck
The 100-card set (48 commons, 20 rares, 12 super rares, and 10 ultra rares) features 10 cards exclusive to Upper Deck and 10 cards previously only released in Japan