If you can force your opponent to spend their gold first on your turn, this is an 8/8 airborne blitz champion which frequently equates to a Flame Strike to the face with an expended, airborne, 8/8 body in play that can potentially draw a card next turn if attacking isnt the best play
Three copies is a good place for cards that have flexibility but arent integral to the core part of your game
If you ever complete a dungeon, that mana ability goes pretty hard, as well
Being able to have a removal spell immediately for Hostage Taker is going to be critical for midrange matchups in Standard, as you cant allow your opponent to untap and cast your threat
The best sac outlets come on a cheap card, have no extra cost to use such as a tap or mana, have no speed restrictions upon their use, and are repeatable
Zell's ability to gain power for the number of lands you control also feels more green, though forms of have popped up in other colors, like the blue, white, and black Dakkon Blackblade