This is the Water Ultimate Power (See 'Falling Stone' for power guide). This one has a little bit of luck to do with it. You need to first let the workers build the tower up a few levels. Upon doing so, continue to play like normal until you have a few Cursed Jars on the tower and a fully charged Tidal wave. Let them get up past where the Tidal wave ability gets, then use it (without charging it up, otherwise it will rise!). Hopefully doing so will not kill any other Jars that either just spawned or you just didn't know about.