Often when I am fighting some random player, I see a gem box or several trees, bushes or rocks that may contain gems. So my idea is to bring a builder to battle.
The builder would take up troop space, possibly 5 (like a giant) or maybe 10 spaces in army camp.
When a player goes to war with a builder they would need to achieve 100% before the builder can be released and he could farm for gems or additional loot (Dark Elixer, Elixer or Gold) with the remaining time. When farming a gem box he would achieve a percentage of the box contents depending on the time allowed to search. Still leaving some for the defending villager.
