Very Creative, I love this idea!
Nice idea! This idea is very unique, has lots of statistics, and is also a troop that isn't extremely complex. This idea is very creative, and the idea of a troop that can be hit by both Ground and Air Defenses seems like an interesting concept. The concept of having passive abilities also seems intriguing. I also find the idea that towers can target it from 4 additional tiles away fascinating, and suggests that the health for the Destructor is very high.
Ability #1 - I think that this is quite overpowered, especially if there aren't any defenses in the area. I think that this should be around 0.5% to avoid this troop being OP.
Ability #2 - A nice idea, but it might also be slightly overpowered, especially if he has recieved lots of damage recently. I think the 20% shield should be needed to around 10% or change this ability to activate every 20 seconds instead, as this is quite a powerful ability.
Question 1 - Can air traps target the Destructor ?
Question 2 - What is his range ?
Question 3 - Would traps dealing damage count towards the Ability #2 shield ?
I would change the Destructor so that it targets any building instead of just defenses, as using 4 of these could wipe out all of the defenses on the map, and use clan castle troops and heroes to help clean up the rest of the defenses. I would also nerd towers abilities to target him from 4 additional tiles away, I personally would suggest 2 or 3 tiles at the most, as X-Bows can already shoot at up to 14 tiles away.
Apart from that, I think that all of th aspects that this tower has are interesting and very different from the rest of the troops. His high housing space requirement might be difficult to fit in with existing attack strategies, but I could imagine some powerful attack strategies involving the Destructor.