Other known variants
x2Spiteful SighPut up to 7 damage counters on this Pokémon. This attack does 20 damage for each damage counter you placed in this way.
Icy WindYour opponent’s Active Pokémon is now Asleep.
If I use Froslass' "Spiteful Sigh" attack to put enough damage counters on Froslass to leave less than 40 HP on it, will its attack be prevented if Blizzard Town is in play?
No, its remaining HP is checked for Blizzard Town before you place the damage counters onto Froslass.
When using Froslass' "Spiteful Sigh" attack, can you put more damage counters on Froslass than it has remaining HP?
Yes, you can.