Genie farm waves 23-25 ruthless hardcore, tested down to ~6k builder stats and seems pretty chill.

Upgrade the buff beam to 3 stars while building, no need to upgrade anything else on this build becuase of the tower boost monk.

During combat use two characters and place them at the marker:

1. Towerboost Monk (wedge him between the golemn and the column).

2. Gaurdian summoner with pets that make it comfortable for your builder stats (I use hunt/monk, or hunt/hunt).

If you are having issues with ogres on wave 24 swap one LT for two seed bomb towers facing the west crystal as in hint 3.

Take care of the spiders, they may hit your tower boost monk if he is not positioned right.