i hate it when u get into a huge fire fight and the whole game lags out...and the next thing i know...im getting pelted with enemy fire and somehow getting slaughtered...:\
Also for challenge#3 you can rush fast units (were-tiger, heroes who ride horses) right under the boss and they won't get hurt. Getting the units under the boss accompanied with berserk and the spamming of rain of arrows, the boss will go down in around 10 minutes :D