Included in packs of bubblegum, the Pokmon Topsun cards were some of the earliest collectibles available for the Pokmon franchise (the Pokmon TCG wasnt released until 1996 in Japan), so they are very valuable to collectors
If the next milled card is a land, you won't take damage, but you keep the rad counter and mill again on your next turn
This smaller price increase comes out to an average value difference of about $150
First strike is a marginal ability that requires blocking to begin with (on one side or the other) and requires that you have more power than the opponent has toughness to even matter (give or take the stray dealing of first strike damage followed by a removal spell)
In fact, only a few always enters tapped
As a touch of sweetness on top of it all, Ephara is very difficult to remove, having indestructible and being mostly intangible as a noncreature until you can bring your devotion high enough (which itself can be easily controlled with flash creatures)