I tried to find a build that was fairly simple, doesn't need maintenance, and is very flexible. The bare minimum towers to sustain leaves a lot of DU left over, so a lot of modifications can be done to speed it up or make up for lower stats

optional towers: physical walls and nature pylon (physical walls help with building at the beginning if you need it)

add another mortar at Hint 1 if it's not enough damage

fill the rest of the DU with west facing mortars to kill end wave ogres faster

HINT 4: DST is optional to kill stuck djinn and wyverns, but I'm too lazy to bulid it most of the time. stuck djinn and wyverns usually at hint 5

I full up but 100% not needed if you're lazy

build hint 1 first

should have enough mana for 2 more mortars (I build 2 at hint 2 to be safe, but 1 is fine if your stats are higher or if you have enough boss dps for nut cracker boss)

use tb/upper for mana to finish building during first combat phase
I use 3 dps and 1 cat buff summ with hunt guard for boss fight. Bosses can be killed via towers, but it might take a long time/need modification