If you can cope with including a couple of lands that don't make coloured mana, there's no reason not to have a Faceless Haven in your deck
The most valuable cards so far include Avatar Aang (Borderless) at around $135, followed by Badgermole Cub, Ozai, the Phoenix King, Sozins Comet, and White Lotus Tile, all ranging between $59-$65
Spellbook decks are all about compiling free advantage through Spellbook Magician of Prophecy, The Grand Spellbook Tower, and Justice of Prophecy, using Spellbook of Fate to interrupt and survive any of your opponents attempts to wrestle control of the duel, and then normally you lean upon a High Priestess of Prophecy to seal the duel
I think this is a junk rare
But in a stalled board the semi-hexproof two drop is often effectively the Abyss, which Thorn Lieutenant never really gets to be