The reason this happens is simply scarcity
This convergence creates compelling dynamics that captivate and engage players
This is because, for the cost of two mana, Zur can convert one of your non-aura enchantments into an enchantment creature with power and toughness equal to its mana value until the end of the turn
"Red-Eyes Darkness Metal Dragon" and "Red-Eyes Flare Metal Dragon", who are the Metal counterparts of "Red-Eyes Darkness Dragon" and "Red-Eyes Black Flare Dragon" respectively but are unrelated to the "Metalmorph" archetype and are not Machine monsters
This only makes landing that first coin flip on tails, all the more important if you want to blitz your opponent
As for removal, "Coven Counters" can use the classic Beast Within to destroy any permanent, and it has flexible boardwipes such as Celestial Judgment , Cleansing Nova and Hour of Reckoning