That is fun but mine is a bit more destructive. Let me explain: /execute lets an entity use a command. @e means that the command targets every entety. So in this example another /execute.Command blocks
/place minecraft:redstone_block ~ +1 ~ 0 Replace
Very fast redstone clock.
/summon LightningBolt
Lets say we have 2 entitys.
the first /execute means that the next command gets executed 4 times. This is an ececute and makes the next command be executed 8 times. The next execute gets executed 16 times and then every enteti gets lightning for each execute thus 16*2=32. Now inmagine it with with a few hundred enteties.