While Oshawott is the only starter Pokemon to appear among the most valuable cards in the set, it's not the only starter Pokemon that greatly benefits from being graded
Note that they must be done in a regular Duel
Trainers Rocket Grunt: Raticate (24), Raticate (24) Rocket Grunt: Arbok (26) Rocket Grunt: Rattata (21), Rattata (21), Rattata (21), Rattata (23), Rattata (23) Rocket Grunt: Zubat (26), Zubat (26) Rocket Grunt: Grimer (23), Grimer (23), Muk (25) Scientist Mark: Magnemite (27), Magnemite (27), Magnemite (27) Rocket Grunt: Weezing (26) Rocket Grunt: Koffing (23), Grimer (23), Zubat (23), Rattata (23) Scientist Rich: Porygon (30) Rocket Grunt: Zubat (22), Golbat (24), Muk (22) Rocket Executive: Koffing (30), Koffing (30), Koffing (30), Weezing (32), Koffing (30), Koffing (30) With key in hand, head over to the Underground and you will be able to open the locked door there and head downstairs
Players gain points for participation, bringing friends to play, and match wins to earn special rewards: a Chocobo art print at 10 points, and a Chocobo Pinfinity AR Pin at 20 points
Then you can discard it with A bao to summon something back from the GY and use Serenade to discard the final card from your starting hand to summon something from deck and make S:P