You can do this to help ensure that a dork slips through for the bounce and draw
For a red deck, card advantage is everything and getting 7 new cards late in the game might just give you enough firepower to kill everyone on the board (or come damn close)
In Living Energy, that might mean repeatedly searching out lands thanks to Solemn Simulacrum (a card that just didn't quite make the cut for this list), making Thopters with Pia and Kiran Nalaar, or tons of energy with Aethertide Whale
Luckily, to simulate the Materia System in FFVII, Clouds Deck is full of equipment to buff him up
You typically cant even participate in tournaments if your sleeves are see-through, even if theres no other evidence of marking in your deck
Again, that it's only for offense means you're not using Goblinball to set up a good block or save your creatures from removal