The Unbreakables Leaderboard
A Leaderboard called something to the effect of "The Unbreakables". To make it onto this Leaderboard, you need to have a minimum of 10 consecutive players who have been unable to "one-star" your base. The players would be ranked by how many consecutive players have been unable to one-star your base. And players in maybe the top 10 receive a reward in gems, once, and the very top player receives a large amount of gems, once. Now here's the catch: if someone thinks they are strong enough, they can select you on the Leaderboard, and choose to attack you. If they can obtain 1 or 2 stars, you are removed from the Leaderboard. If they can obtain 3 stars, they get extra loot, and you are removed from the Leaderboard.