On top of that, it reads: At the beginning of your next main phase, add an amount of colourless mana equal to that spells mana value." Basically, not only do you get to say no to something, you also get to cast something bigger on your next turn
You can only Special Summon "Icejade Kosmochlor" once per turn this way
Regardless, what we have now is a Standard format that looks great while also giving players the ability to choose between a number of different strategies
Thousand-Year Storm While this card is hilarious, it was very tough to make it work since you basically had to take turn 6 off to use it, and your deck also had to have enough cheap spells to get it going
It's also great with other artifacts to make this bigger in the power
If either of them is tails, that Pokmon is still Asleep