Although there are no Rock-type Pokemon in the TCG, they are replaced with the Fighting Energy, which groups together Rock, Ground & Fighting types
There is one that players have been consistently subbing in, and there is one I actually like using a bit better, depending on the circumstance
A deck that focuses on ramping up mana quickly, such as a green ramp deck, would benefit from using Explore as it allows for playing an additional land and drawing a card in the same turn, providing both card advantage and mana acceleration
At face value, Whirler Rogue looks like a very good Limited card
Paired with more recent series or with Crown Zenith, it lets you trace the evolution of the game and its mechanics
A deck built around Eruth, Tormented Prophet can run a quasi-infinite combo with Birgi, God of Storytelling, Underworld Breach, and Burning Inquiry