A 5 mana card that is currently not legal in ANY format, Nerf War was an unofficial joke card
Ill think of a mermaid lagoon Oh, underneath a magic moon Ill think Im in a pirates cave Theres no space left in Fabled for Never Land Mermaid Lagoon, which features the ominous Skull Rock in the background
Forcefield ($470) - This card is designed to keep you alive in MTG, allowing you to lose only 1 life to an unblocked creature
Apart from the issue of some cards not having playable substitutes, the other reason I tend to dislike this advice is that part of what makes formats like Commander fun is the diversity that they offer, and this diversity is built, in part, on players being able to access and play with weird, old, nostalgic cards that don't really see play in other formats
Pikachu 19/68 is a Common card and belongs to Common cards of Hidden Fates series