New spell: Suppression

It's a spell that decreases the damage of troops defenses and traps in its area of affect.
Elixir spell
Housing space:4
Cost:63000
Type: area of effect
Area affected: 10 tiles
Damage reduced: 20% goes up with upgrades
Duration: 10 seconds: goes up with upgrades
Can be used for an air attack to decrease damage of air defenses and air mines.
For ground push could decrease damages of infernos Eagle artillery and giant bombs, etc.

Tell me what you think

Poison spell reduces troops attacks, speed, and health.

Freeze spell stops all attacks from defense and troops.

Why have a spell that only reduce attacks when there are already ones that does the job better?