Originally Posted by Drynix

Stage 4 is hard. You need to use the cannons. I placed 2 squads at the bottom camp, 1 to take the lower route and kill the pest, 1 to take the upper route and fire the cannons. The other 3 were located at the square surrounded by cannons with 3 charges. This way all shots were fired.

Hard? It is actually pretty easy, you don't need to use the cannons, they only do a small damage on the pest and can be totally ignored.
All you need is a fast team at the lower camp, so it can reach the bottom boss before the stage ends. My main team has balanced speed, so i didn't even had to change the position of anyone to clear it. If you don't clear it at the first try, just place the slowest team at the top and the fastest at the bottom. Also, you can remove the character on the webs camp, there is nothing there (the character will be struck there and won't leave)
You only really need the cannons if your team is not very strong (less than 60k power)

This was without a question the easiest of all events until now, I completed all maps at the first attempt, only ?-3 need a setup (moving a character to the top right camp).