They worked off discarding themselves to gain effect, though while Dark World monsters had to be discarded as cost, Fableds could be discarded for any reason at all
So knowing this about Drowzee and looking at this Hypno card, you can either set this line up on the bench and utilize Hypno's Ability, or start the game with Drowzee in the active Pokemon spot and then evolve into Hypno and do 50 damage a turn
Special Summon "Congester Tokens", up to the number of Link Monsters your opponent controls
Mewoscarada, Giratina Ex, Red, Pokemon Center Lady, and Iono are all worth collecting, but with Darktina decks mostly out of the meta, Giratina Ex is seeing a lot less play, and the supporters are typically played in single copies