The price moves around, but nothing else in the Final Fantasy set is even close.The Neon Ink variants of this same card are expensive in their own right
This Horses power and toughness are both equal to the number of Swamps you control, oftentimes making it a 6/6 by the time you cast it since it has a cost of six mana
Abilities on Lands are great for this, too, whether activated like Rogue's Passage or Creeping Tar Pit, or modal like Valakut Awakening // Valakut Stoneforge
If the squids triggered upon leaving the battlefield instead of at death, Id say that it might compete with True-Name Nemesis in Legacy
More recently, it seems as though Wizards has been trying to fix this with a bit of color bleed with cards like Esper Sentinel
Coat of Arms is arguably the most important because each creature you control gets stronger for each other creature you control of that type