New hero idea, and new troop

First I apologize if someone else has already come up with these ideas and posted them. But my first idea is , when your heroes are on guard and your village is being attacked , when their health reaches 50% it should turn on their ability , I mean you can use the ability while attacking , I think that the ability should be able to be activated on defense as well, this would make for the attacker to check its strategy, and would also decrease the chance of the hero (mainly the queen) to be killed by lightening spell if the user has the queen near an air defense and the attacker zaps her , the queen would disappear summon archers , and regain health when her health hits 50% which would mean she would still have a chance to defend .

My second idea is --
Dark elixir x-bow/cannon
Usable during attacks , if a user needs to load it , instead of it instant reloading like x bows , it requires times loading because dark elixir is deemed unstable so it must be carefully done.
Similar to the grand warden, it has the ability to be set for defense on a base, but it also has the ability to be taken into battle , when set for defense it would be more powerful because it's "stationary" but can swivel In a range like the air sweeper , can be set for either ground , or air similar to the x-bow . When taken into battle it will be shown it being carried by a giant (based on the level Giants the user has) the x-bow will be shielded until the giant dies , when the giant dies , the x-bow then begins to be stationary , and range then works as if it were defending your base , now it is vulnerable to attacks since its defending/shielding giant is destroyed . Attack range varies but similar to the x-bow
Level 1 50 DPS 1,500 HP 360 DE to load
level 2 70 DPS 1,900 HP 490 DE to load
Level 3 90 DPS 2,300 HP 620 DE to load (max level)
Range would mirror the air sweeper level 3.
Load times would be --
level 1 6 minutes
Level 2 12 minutes
Level 3 18 minutes.