Don't use them in Pokemon leagues or something similar, as they're not legit
By buying Pokemon 151 PTCG Live codes, you can possibly acquire the following cards: Venusaur ex, Charizard ex, Blastoise ex, Pikachu, Ninetales ex, Wigglytuff ex, VIleplume, Meowth, Alakazam ex, Golem ex, Gengar, Kangaskhan ex, Chansey, Starmie, Jynx ex, Gyarados, Ditto, Eevee, Zapdos ex, Dragonite, Mewtwo, Mew ex, Erikas Invitation, Giovannis Charisma, Illustration Rare Charmander, Illustration Rare Squirtle, Illustration Rare Bulbasaur, Full Art Charizard ex, Full Art Blastoise ex, Full Art Venusaur ex, and more
Witch-King of Angmar, for example, only costs $3 at its cheapest
And Smells AMAZING
Even if you are not abusing your life total with Necropotence there is a good chance you have some cards that can or do cost you some life although probably no where near enough to be killing you it will mean you are effectively on a lower starting life total
2 Trainer PSA 9 MINT ($110,000 USD) 6