Impossible Warrior - no losses?

[Zhuangzi]

I don't think level 5 units are essential, but they are nice for absorbing hits I guess. A lot of people seem to like Cyclops but I highly recommend Red Dragons if you can find them.

For me the hardest part of the game so far was roughly from battles 50-120. That part dragged on for a long time and I did a lot of island hopping to fight the weakest possible enemies. 120-250 has been much easier.