Spend energy wisely. Only hire the exact number of knights required to kill the boss + Strong friends.(I hit 60 with 36 hours left on Asherah) - Some people even set their alarm when they go to sleep so they can wake up and kill boss and head to bed again. I have reached 60 out of 60 4 times now and its NOT needed to spend any gems at all. It can be done even though you only have 1 armor with 1 elemental advantage.