Somehow, this card made it out of the machines alive, and the odd placement just makes it even cooler
VSTAR Cards Introduced in late Sword & Shield sets
It also was in the Lure + Thicket Basilisk + Regeneration combo that was beloved back then too
Typical early examples include Thraben Inspector (When this creature enters the battlefield, investigate.) or Tamiyo's Journal (At the beginning of your upkeep, investigate.)
The card art shows AC's science-fantasy interpretation of the mythical blade, just as it appears in 2020's Assassin's Creed Valhalla - where it was a powerful endgame weapon found by unlocking a secret chamber under Stonehenge
In many ways, Mithril Coat is the new Lightning Greaves or Swiftfoot Boots, being cheap equipment that serves mainly to protect a creature