Look for a lighter color on the card's back, unusual flexibility, or exaggerated attack values
Often the engagement then actually gets in the way: you end up ticking off specific tasks within a match, rather than playing the game itself for its own good, and only come back for extrinsic rewards: skins, XP, packs, or whatever else
In addition, this Pokmon definitely deserves to be on this list thanks to its ability to learn one of the most powerful Rock-type moves introduced in Generation V, Rock Wrecker
Since it's an artifact, you can cast it if exiled with Chiss-Goria's attack
Basically if you have 3 creatures in play, with Thaumaturge being one of them, and a Dragon Tempest in play, you put 12/12 worth of Dragons into play and instantly do 9 points and then attack for 12
The 30th anniversary has fanned the flames, with prices reportedly up more than 100% year over year