MArcomage

I do not understand the effect

I think the effect is like this:

Enemy tower -N
N = you tower height

The current text has made the effect more confusing.

Enemy tower -N
N- own tower (no change in process)

Just have it say:

Enemy Tower -N
N = your Tower height

Using a dash makes it look like you're trying to subtract something, especially when you used one in the previous line.