Final-Word Phantom's last ability applies only to casting spells
He just also happens to have a Spark
This makes this card a lot more viable when put into context
This sees a lot of play because it is versatile in which combos it works with but also because it is the most effective card in a few specific applications, the beating of red and green players being the primary one of these but also for other matchups where you need to dominate the board and immediately take all the tempo
It turns the luck factor up to eleven, something that frustrates competitive players who prefer crafting game plans, matching wit, and besting their opponent intellectually
While Vadrik can interact with the Day/Night mechanic of Innistrad: Midnight Hunt, what's truly important about the card is that, as a 1/2 for three mana, Vadrik uses his power to reduce the cost of instants and sorceries