Explain why they should be taken down?
When I took them down using codes, I didn't get anything!
Maybe it's because I didn't have enough wisdom!?

Then explain why you are chasing Armageddon so hard?

Offline is a tournament for maximalists! Everything that moves must be killed, everything on the map taken, etc. The time limit of the maps is always set so that the best players can achieve this.
The question "why" is essentially rhetorical. Whoever manages to do it will get 4-5 levels of experience for their main hero. Whether this is necessary or not depends on the choice of the main hero!
Armageddon is a good spell. Especially against water elementals! Again, whether it's needed or not is a matter of taste.
But to learn it, you need more than just wisdom—you need what Zingel pointed out first! ;)