Incomplete idea

So I have an idea build on it if u think its a good one. Instead of attacking someone and ur units being demolished buy a few mages in an out of reach are, what if there was a unit that went after the clan castle and went undetected by the units in the clan castle, and when the clan castle is destroyed the units inside die too

DE unit available at TH9
Cost of unit: 1000 de
Attack:
Lvl 1 20 dps & 1500hp
lvl 2 25dps & 2000hp
Lvl 3 25 DPs & 2500hp

Favorite target: clan castle
Ability: undetectable by units in Clan castle

So that's my idea, help me improve it, thanks for reading