Hint 1: Aurastack (Lightning, Strength Drain, Ensnare). 5 DU Buffbeam blocking the hallway. 1 DU Reflect behind the front Buffbeam. 4 DU Buffbeam behind the reflect with 3x Lightningtowers on. Minions: 4 Archers, 1 Mage, 1 Spider (Spread them out so ogres cant walk past).
Hint 2: Aurastack (Lightning, Strength Drain, Ensnare). 4 DU Buffbeam. Minions: 3 Archer, 1 Spider, 1 Mage.
Hint 3: Aurastack (Lightning, Strength Drain, Ensnare) south of the crystal as close as you can place them. 6 DU Buffbeam from the middle of the south staircase to the edge of the east staircase. Minions: 5 Archer, 1 Mage.
General info: The first wave cam be tricky cause you will not have enough mana to build everything. I would start by opening the DDR room and building auras. Dance once to open the Fishbowl room for more mana. You should have enough mana to build everything except all the minons. Focus on building minions on Hint 1 if you have time, or be on a dps to deal with the Ogres that spawn.
GL and HF