For each heads, take a Water Energy from your Energy Zone and attach it to that Pokemon
One thing we've seen happen in the past is that when a popular supplemental product comes out shortly after a Standard set, the Standard set is sometimes forgotten and under-opened as everyone spends their money on the supplemental product
When one is in the yard, whenever a creature with at least a six cost arrives, you can put the aura right on that creature
Search by name or number, filter by rarity, type or price, and sort the list your way then mark off what you own as you build the set
I like it most in decks with expensive commanders that can be made cheaper or ramped out
As Wizards itself admits, the term 'proxy' can sometimes be used colloquially for either