After all, the four share a lot in common in terms of name, function, and their place in the series's world
If you close the game before making the booster pack pick and open the game again, you can see what cards are automatically added to your collection
For Rocky Helmet, the opponent would have to think very carefully if getting some early attacks would be worth putting their currently active Pokmon into one-hit knockout (OHKO) range, thus denying an easy way of just attacking your currently active Pokmon
Extra turns mean extra combats, which means digging for more extra turn cards
Tatterkite For a while in design we used the text "CARDNAME cannot be countered." Then templating told us that some other ability was already using that string of words
For example, if an opponent draws a second card, casts a second spell, and attacks you with two or more creatures in a single turn, Trouble in Pairs's last ability will trigger once when each of those events occurs, for a total of three times