Players use decks of cards that generate five colors of mana, and play cards that consume mana to call for creatures, cast defensive and offensive spells, and activate effects or unique abilities
Expensive, yes, but it blows up anything
Colorless mana costs for a card can only be met with sources that produce colorless mana, and cannot be met with any other colored mana source, compared to "generic" mana costs which can use any colored or colorless mana source
But the repeatable, colorless, Carnage Altar has been the class at for many reasons
A ramp spell that is also a win condition early Magic sets were pretty busted
Its also a great idea to take photos or a short video of you packing the card to serve as proof of its condition and your careful packaging