This means you can Chain block to get the effect you want to resolve to be guaranteed, as opponents can only Chain to the last card in the Chain
While it has frequently been maindecked, its also been a popular sideboard card, perfect for grinding out attrition-based post-sideboard games, such as the Kithkin deck Cedric Phillips piloted to a top 8 finish in PT Kyoto 2009: Creatures (20) Planeswalkers (4) Lands (25) Spells (11) Sideboard Nowadays, the idea of aggro decks slowing down and going bigger after sideboarding is commonplace, but Cedrics use of it here was especially futuristic for that time period
Most ways to get creatures onto the battlefield without spending mana do so by using cards in the hand, so pairing these with this card is fantastic synergy
The former doubles a creatures power and toughness until the end of turn, while the latter has the spell deal five damage to a creature with flying
Honorable Mention #2 (#12 Overall) - Laser Screwdriver AND Sonic Screwdriver Mana rocks might be boring picks, but mana matters