"If we knew what we were building, it wouldn't be called research!"
Sufficiently advanced mathematics is indistinguishable from magic
Bernhard Vierthaler wrote:
So the if he chooses the number 3 all spells with a 3 are blocked, even if I want to play them with my Cinderblast Dragon?Yes.
The spell is still treated as having a cost of 3, even if you don't have to pay that cost thanks to Cinderblast Dragon.
In the same way, Insurance Agent will still pay you $9 if an insured Gigadon dies, even if it only cost $1 to play, or arrived free via a Sanatorium.
Temporal Distortion can return a Gigadon and get you any Tech II unit that costs $9 or less, even if you only paid $1 for the Gigadon.
And indeed, True Power of Storms still considers Morningstar Flagbearer to cost $3, even if River Montoya's maxband means you'd only need to pay $2 to play it.
Everything that looks at a card's "cost" or "gold cost" looks at the number printed in the top right, regardless of what it actually might have cost to play due to assorted cost-changing effects.