You can use them in either the standard or the now, mostly unsupported extended metagames
Black Yellow Monkey D.Luffy 1xST13-003 4xEB01-056 4xST13-013 2xST13-012 4xOP06-106 4xST13-007 4xST13-014 2xST13-010 1xST14-006 1xST13-005 3xOP02-114 4xOP04-083 4xOP07-109 4xST13-015 2xST13-011 4xOP06-086 3xST13-019 Black Yellow Luffy is still holding its own in OP09 meta, even though the deck didnt receive any new support in OP09s release
Glaive of the Guildpact Medieval warfare enthusiasts (half of a Venn diagram that overlaps with Magic fandom a considerable and surprising amount) will be the first to tell you that a glaive is a polearm weapon similar to a halberd, or more closely a naginata
The Golden Rule: The most expensive cards usually combine High Rarity (SIR/SAR) + Popular Pokmon (Charizard, Pikachu, Eevee, Gengar, or Waifu Trainers)
For those of you who have played Magic The Gathering in the past, you are probably more than familiar with formats like Modern, Legacy and Standard