Trainers » Megaton Blower
Can I use Megaton Blower if there's a Stadium in play but my opponent doesn't have any Tools or Special Energy cards in play?
Yes, you can. Discarding the Stadium is not reliant upon discarding any other cards in this case.
Source: Surging Sparks FAQ; TPCi Rules Team (2024-11-07)
Trainers » Megaton Blower
What happens if I play Megaton Blower and there's not a Stadium, a Tool, or a Special Energy in play?
You can't play the card for no effect, but if there is at least one of those types of cards in play you do as much as you can.
Source: Surging Sparks FAQ; TPCi Rules Team (2024-11-07)