This gives the player an advantage in that their opponent is forced to either damage themselves or allow them to recast a potentially game-winning creature
Richard Garfield Leaving Hasbro Since then, Garfield has created multiple games that are still popular today
The archetypes which want those kinds of cards are red-white, green-white, black-red, and (to some degree) green red
View Prismatic Evolutions products Top 3 most expensive cards (average market value at release): Umbreon VMAX Alternate Art (~900) Sylveon V Special Illustration Rare (~450) Espeon V Illustration Rare (~350) With these prices in mind, you can look at current prices via Cardmarket, for example, and you will see what enormous price developments have taken place
They are considered rare and highly sought after by collectors
Rosheen Meanderer is another incentive to cast hydras with X in their mana cost