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Even better if the foe was already almost dead. When you slap something for huge numbers it's also fun having the DM describe the wreckage that's left of your opponents.
I feel like some Table Top games are more prone to this than others, just based off watching some different IP's being played.
Have you played 10 million hp planet? It's built around this concept, the endgame is bashing an entire planet to pieces. And you start with just d6 damage! If you love stupidly epic over-the-top ridiculousness, this is the perfect game!