The Dark/Dragon typing gives it crossover appeal between two of the most popular type communities, and the SIR format showcases the design in a way that standard rare and ultra rare printings simply cannot match
Beyond the raw value, Teysa provides a defensive safety net by granting your creature tokens vigilance and lifelink
The answer to this is: yes and no
The Raichu-themed one, for example, is currently going for $51 on eBay
Lutri, the red/blue companion, has been banned in both formats because its deck-building restriction essentially makes it a freebie for URx decks
While many of us can opt into a house rule to allow or disallow silver-bordered cards, players without a regular group must rely upon strangers they encounter in their local game stores