You have many cards like Bloodghast, Cordial Vampire, or Drana, Liberator of Malakir that are better when cast on curve and reasons to have few Plains in your deck
However, the big driver of these massive sales is the condition
Outland Boar: reasonable uncommon in battlecruiser
You can only use 1 "Priestess with Eyes of Blue" effect per turn, and only once that turn
On Watermelons (Japanese) blog, on their list of old back articles there are these two articles linked that cover dozens of Base-Neo differences between Japanese and English: Daydream Holic Night 1 : Daydream Holic Night Jason(neo1) Daydream Holic Night Neo : Daydream Holic Night 1 Jason has called out many of these errors, and some other English/JP differences dont affect gameplay in this era, but there are quite a few more that are mentioned that would affect actual game mechanics, but havent been called out in this thread (nor are they mentioned in the Compendium)
A terror on the battlefield since its inception, Wurmcoil has been a staple in EDH for as long as I can remember