Lorcana is coming off a 4th set championship, and players have received their first game-changing errata to a card that was seeing a lot of consistent play: Bucky
1 Lightning, SecuritySergeant
Celestine, the Living Saint Celestine herself will set up a Sun Titan-like trigger after she deals damage, although its just for a creature and not any permanent
As a three-mana 4/3 creature, Casey Jones is a great big hitter for the mid-to-late game even without the card draw, but the ability to draw three cards once he hits the battlefield is a major win for red decks
Like most Magic: The Gathering cards, the value of Swiftfoot Boots depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (The Brothers' War Commander)
While this effect does become quite dominant in those super late game scenarios they occur so infrequently you don't want to over do it on improving that aspect of your game