While upgrading and having summoners out, place huntress/huntress and monk/monk guardian pet summoners at [Hint 3] and a huntress/apprentice guardian pet summoner at [Hint 1].
When you are finished upgrading, switch to an apprentice/apprentice guardian pet summoner to buff the [Hint 3] tower stack and the Strength Drain aura.
The aura stack at [Hint 3] has the Strength Drain aura on the tower stack and the Ensnare aura against the east of the crystal.
[Hint 1] is built on the tall vase. [Hint 3] is built on/in the spikey plant bush thing that is closest to the "stair-ladder".