To make this easier to get you first need to let the builders make the tower quite tall because you are going to aim for the top when the toper reaches a pinicale in the spiral.
I recommend level IX where you have to fend off boats.
Now all you have to do is build up your super ability and when you have it scroll to the top of the tower aim just on the row just bellow centre and unleash your Meteor Shower. This should knock out more than the 5 blocks required.
This is also a good time to get the following achievement if you do not have it yet:
The Holy wave achievement in Babel Rising worth 23 pointsUse a tidal wave that spares cursed jar bearers. (Campaign, Survival)