New building idea: The spell scrubber

Hey everyone this is my first post ever so please have mercy! I was thinking we could have a hidden building similar to the hidden tesla but called the spell scrubber tower. As the building is triggered it slowly starts to scrub out an area starting at the epicenter, of any spell that has been or is deployed. As each second passes the diameter increases according to the level in which the tower has been upgraded.

So:

The spell scrubber tower
3 million gold for lvl 1 and maybe only 3 upgrades so it doesn't go too far ?
Building time could be similar to an xbow or inferno
Hit points could be its major flaw so it's not a total game changer.