He and Declan had to Set five cards in order to negate the effect and double their monsters' ATK, but to use this effect they would have to to skip their Draw Phase and would only be able to Set one card each turn
Each Draft Booster contains 15 cards and 1 token/ad card, including 12 cards of rarity Rare or higher, 34 Uncommon, 9 Common, and 1 Land cards (Full-Art Showcase Land in 33% of boosters)

Sort Card Type Swirlix #93Common $0.16 Swirlix #24Common $1.28 Swirlix #94Common $0.30 Swirlix #68Common $0.45 Swirlix #RC19Uncommon $18.64 Swirlix #153Common $0.28 Swirlix #67Common $0.19 Swirlix #83Common $0.25 Swirlix #89Common $0.10 Swirlix #67Common $0.13 Swirlix #51Common $0.09 Swirlix #47Common $0.27 Swirlix #28Common $0.30 Swirlix #62Common $0.84 Swirlix #23Uncommon $21.00 Swirlix #61Common $2.68 Swirlix #42Common $1.00 Swirlix - 9/12 #9Promo $6.81 Swirlix (Energy Symbol Pattern) #93Common $0.26 Swirlix (Love Ball) #93Common $0.32 Swirlix (Master Ball Pattern) #67Common $2.82 Swirlix (Mirror Foil) #67Common $0.70 Swirlix #23Uncommon $21.00 Swirlix #RC19Uncommon $18.64 Swirlix - 9/12 #9Promo $6.81 Swirlix (Master Ball Pattern) #67Common $2.82 Swirlix #61Common $2.68 Swirlix #24Common $1.28 Swirlix #42Common $1.00 Swirlix #62Common $0.84 Swirlix (Mirror Foil) #67Common $0.70 Swirlix #68Common $0.45

anime, during the Duelist Kingdom tournament, Toon monsters functioned the same way that they did in the manga
The Ur-Dragon is the quintessential dragon commander, making your dragons cost 1 less even from the command zone while allowing you to play any color of dragons in your EDH deck