While toughness is typically a measure of a creature's defensive ability, the printing of cards like Assault Formation, which allow creatures to assign damage equal to their toughness, has made these creatures sought after for toughness-themed decks
The best quick play spell is Runick Tip due to the sheer versatility of the card, and it reads as follows: Activate 1 of these effects, but skip your next Battle Phase after activation
The Ur-Dragon is potentially the most powerful Dragon commander with its 'eminence' ability making the rest of your Dragons one generic mana less to cast, even if The Ur-Dragon isn't on the battlefield
But its real purpose is its other ability: Whenever a creature an opponent controls is dealt excess noncombat damage, amass Orcs X, where X is that excess damage. It can be a great source of Amass Orcs and it is a part of a 2 card combo with Blasphemous Act that results in near-infinite +1/+1 counters on an Army token and near-infinite damage to all creatures
I firmly believe that given the soapbox that Sheldon and the other members of the Rules Committee have an article extolling the virtues of playing with un-set cards and a sincere personal recommendation to try it would have been enough