Ok, at first I tried to build a deck just with Dark Slowking but I found out that it doesn´t hit hard enough. So, I build the following deck:
3 Dunsparce - only need 3 because of Swoop - discarding basics doesn´relly matter (retriever)
4 Slowpoke
4 Dark Slowking
4 Rocket´s Sneasel EX
4 Darkness Energy
6 Psychic Energy
2 Rocket Energy
1 Double Rainbow Energy
2 Dark Metal Energy
3 Copycat
3 POR
4 Swoop - better chance for good start, search for Slowpoke, do dmg with slowking
2 Retriever
3 Reporter
3 Rocket´s Mission - don´t know which one´s better here
2 Pow
2 Rocket´s Hideout
2 Switch
2 Rocket´s Pokéball
4 Advice
3 Dunsparce - only need 3 because of Swoop - discarding basics doesn´relly matter (retriever)
4 Slowpoke
4 Dark Slowking
4 Rocket´s Sneasel EX
4 Darkness Energy
6 Psychic Energy
2 Rocket Energy
1 Double Rainbow Energy
2 Dark Metal Energy
3 Copycat
3 POR
4 Swoop - better chance for good start, search for Slowpoke, do dmg with slowking
2 Retriever
3 Reporter
3 Rocket´s Mission - don´t know which one´s better here
2 Pow
2 Rocket´s Hideout
2 Switch
2 Rocket´s Pokéball
4 Advice