By forcing white-blue Knights, my favorite archetype, and selecting Swordsworn Cavalier as a high priority pick, I was able to create a potent, tempo-driven deck that favored an aggressive playstyle
So, say you need two Fire Energy, and this card will fulfill it
Not to mention that Calhoun herself likes to challenge other characters on the field
Thanks to the built-in resilience of Earthbending, theres little risk to animating your lands with it
Most other decks have haste creatures, flash creatures, or large numbers of small creatures, and those arent what Tamiyo wants to play against
Cards allowed in tournaments are reevaluated yearly and adjusted as needed, but casual games can always use some overpowered cards as long as everyone agrees to it