The mana discount is sizeable, and the haste will often be incredible, especially in conjunction with attack triggers such as Raksasha Debaser, Balor, and Lord Xander, the Collector
Its Lost Impact attack swings for an impressive 280 damage, with the only drawback being to putting two Energy attached to any of your Pokemon in the Lost Zone
A much better cost is two or three mana
Flexible Removal: Similar to silver bullets, some decks will want cheap and efficient ways to deal with threats, especially in aggressive matchups
Thats why I stressed the many other themes you can build into a discard deck before getting to this one
The Supporting Cast Brainstorm, Ponder, and Sensei's Divining Top help you to set a good card on top of your library to suspend with your commanders ability