You can’t pay more energy counters than you have.
If an effect says you get one or more , you get that many energy counters. To pay one or more , you lose that many energy counters. Any effects that interact with counters a player gets, has, or loses can interact with energy counters.
Energy counters are a kind of counter that a player may have. They’re not associated with specific permanents. (Other kinds of counters that players may have include poison and experience.)
If the target creature or Vehicle becomes an illegal target while Aether Meltdown is on the stack, Aether Meltdown won’t resolve. It won’t enter the battlefield and you won’t get .