Latias, Latios, and Pikachu were reprinted in North America in the EX Holon Phantoms set, while the others were reprinted in the Pop Series sets
Given the heavy Dragon theme implied in the first wave of reveals, its very likely that the good Dragon cards already in Standard could experience spikes such as these

Other printings of Flaaffy $4.91 Flaaffy Fusion Strike $15.00 Flaaffy Aquapolis $3.47 Flaaffy SWSH Black Star Promos $1.79 Flaaffy Scarlet & Violet Black Star Promos $6.15 Flaaffy POP Series 7 Flaaffy Scarlet & Violet Black Star Promos $3.86 Flaaffy Neo Genesis $2.89 Flaaffy Expedition Base Set Most valuable cards in HeartGold & SoulSilver View the full price guide $182.02 Lugia LEGEND HeartGold & SoulSilver $168.40 Lugia LEGEND HeartGold & SoulSilver $124.97 Gyarados HeartGold & SoulSilver $119.02 Ho-Oh LEGEND HeartGold & SoulSilver $79.21 Ho-Oh LEGEND HeartGold & SoulSilver $58.89 Alph Lithograph HeartGold & SoulSilver $44.59 Darkness Energy HeartGold & SoulSilver $39.15 Typhlosion HeartGold & SoulSilver More cards by Masakazu Fukuda $2,088.55 Pikachu Holon Phantoms $1,999.99 Vaporeon Power Keepers $1,504.99 Mew Dragon Frontiers $1,400.00 Mewtwo Holon Phantoms $1,399.00 Gyarados Holon Phantoms $1,199.99 Metagross Delta Species $999.99 Kyogre Delta Species $999.00 Charizard Dragon Frontiers Lightning typeLightning type Pokmon cards SetHeartGold & SoulSilver Most valuableTop 100 Pokmon cards You might also like...

The fun continues in January with another concept pack set: the Sun and Moon Strengthening Expansion Pack will be released on January 27th, 2017
Some examples of notable patterns include: Tinsel Holofoil: Used from the Black & White to Legendary Treasures sets, featuring horizontal stripes across the image and, in Japanese cards, a tinsel effect on the border
Having a consistent way to sacrifice your own creatures in this type of build is always important, especially if that sacrifice outlet doesn't cost you mana