Sort Card Type Misty's Seaking #55Uncommon $2.56 Seaking #59Uncommon $14.85 Seaking #60Uncommon $1.52 Seaking #46Uncommon $1.13 Seaking #37Uncommon $2.30 Seaking #21Rare $1.04 Seaking #21Rare $0.78 Seaking #24Rare $1.33 Seaking #62Uncommon $0.44 Seaking #43Rare $1.63 Seaking #28Uncommon $0.20 Seaking #49Rare $0.26 Seaking #47Uncommon $0.10 Seaking #119Uncommon $0.17 Seaking #45Common $0.15 Seaking #21Uncommon $0.16 Seaking #29Common $0.12 Seaking #27Common $0.08 Seaking #119Uncommon $0.11 Seaking #11Common $0.61 Seaking #10Uncommon $0.94 Seaking #14Common $0.99 Seaking #13Uncommon $0.18 Seaking #14Uncommon $0.03 Seaking (Master Ball Pattern) #21Uncommon $2.92 Seaking (Master Ball Pattern) #29Common $3.75 Seaking (Master Ball Pattern) #119Uncommon $10.43 Seaking (Mirror Foil) #29Common $0.64 Seaking (Poke Ball Pattern) #21Uncommon $0.49 Seaking (Poke Ball Pattern) #119Uncommon $0.65 Seaking #59Uncommon $14.85 Seaking (Master Ball Pattern) #119Uncommon $10.43 Seaking (Master Ball Pattern) #29Common $3.75 Seaking (Master Ball Pattern) #21Uncommon $2.92 Misty's Seaking #55Uncommon $2.56 Seaking #37Uncommon $2.30 Seaking #43Rare $1.63 Seaking #60Uncommon $1.52 Seaking #24Rare $1.33 Seaking #46Uncommon $1.13

This is the same exact card from the set, there's no difference confirmed
X, Prime, EX, etc..) Generation 3 introduced Pokemon ex, which were a higher rarity than Holo Rares and placed after Special Energies in International Sets (but before Secret Rares and Basic Energy Cards.) Japan sets would include these in the main set alongside Common, Uncommon, and Rare Pokemon
As a result, it deals an extra 20 points of damage to the attacking enemy
It cares about more expensive spells rather than just cantrips and cheap interaction, so it plays a little differently than typical spellslinger decks
They were also the last two trainers left, so there were no more trainer battles to be had