This map can be tricky, and is heavily dependant on where the portal teleports to. The markers (aside from the 1 that marks where the towers are located) are where the increasingly risky spawns are at. 3 Is problematic with lower stats and even with high stats some spiders might slip through. 4 is almost definitely going to bring you some problems and might require a DPS Summoner to baby sit it. 5 Needs a babysitter summoner otherwise you wont survive multiple waves of it.
At that start of each wave check where the portal is and make judgement according to that.

How to build it:
1. Start the map with your EV and place the 4 DU buff beam.
2. Depending on if your EV or Apprentice is faster use either to gather the mana (don't forget the shroomites).
3. Start with the most northern stack and place the 6 DST and 5 LT according to the diagram.
4. Bring in a second character as an Initiate Booster (I found the increased range/fire rate from Initiate more effective than Monk Tower Booster for this) and start the wave. Drop 800+ mana to your Apprentice and then start Initiate Boost.
5. As your Apprentice build the 2 DST pointing south first, then follow up with the 5 LT.
6. Swap back to your Initiate and you can cancel the boost to use the mana to upgrade the buff beam to max level.
7. New wave starts and swap out your Apprentice for an regular Monk Tower Booster. 
8. Now here you can choose, I found putting in your third character as the Apprentice that build the towers to be most effective. This might be stat dependant so another alternative (but requires more attention) is to bring in a DPS Summoner that babysits the portal.
9. Continue through the map with a character setup that works for you. At the final wave add in either the DPS Summoner or Apprentice builder, whichever you have left over.