Rare Candy helps Litten evolve in no time and in the meantime, you can account for the 3 Energy using good ol Moltres EX
Being able to put 130 damage on board for 1 Fighting on a 1 point Pokmon is freakishly efficient regardless of the downside, and its big weakness of being a Stage 2 can be mitigated by "Rare Candy", meaning the only real issue with "Rampardos" is its Basic form not being searchable with "Pok Ball" due to being a Trainer Card
Madness decks are the obvious home, but recent cards like Inti, Seneschal of the Sun and Rielle, the Everwise have expanded the list of cards that encourage you to discard cards
Duplicate copies affect catalog breadth, cash conversion, storage, photography, and customer perception
You dont know if youre going to draw the Reanimate, so you need to carefully consider if its worth discarding the Archon and exposing it to graveyard hate without knowing when the reanimation spell is coming
Since a deck is limited to only four copies of a non land card usually, this added diversity comes at the cost of significantly reducing the chances of getting a certain card in a given game