This is a great game, simple and yet addictive. If anyone finds it hard to kill the BIG SHIPS, just use SHOCK AND AWE till it pushes the BIG ship over the border so it wont fire anything (specially when BIG SHIP spam you). then let 1 BIG SHIP get back in then attack it till it dies, if the others comes back again, just push them over the border again.
Chaos mage is a good choice....the GREAt skill of chaos mage that can defeat every clan even the most powerful mage is a) silence, b) make every 1 damage and 3) if low on HP, Trade life. Easy win, try it.