lvl 7 units and evolvement

Add lvl 7 units but when they reach lvl 7 they dont just be stronger but and a another power too
Ex.
Barberian have x2 damge to troops that coming from clan castle when upgraded to lvl7
Archer: 20% chance that can damage all building in front of it
Goblin:move faster and ability to chose which loot i wany him to take for u for example if u want DE u click at DE and it goes only for DE
Gaint:no effect from mortars
Ballon:x2 less damage from wizard towers
Wizard:chance of 20% to freeze def for 2s or chance of 50% to burn other building
U can get all of these when u upgrade your troop to lvl 7
Ps.sry for bad english