Dispose of Monarch first since that Insector will move forward to assault your team. Make sure to defeat it before the enemy turn. Atually for this round whenever you are attacking an Insector it's wise to defeat it in a single turn. Reason is Dark Shell will definitely heal it's injured allies in the next turn. You might want to try killing Dark Shell but that Insector will stay at the back. It's a bad idea to move your Insectors forward just to kill it. If you find the healing Insector coming your way then defeat it otherwise make sure to kill an Insector in a single turn. As such Dark Shell won't have the chance to heal anyone. Always stay at the back; group as a team so you can assault an Insector with all your five allies at a time. You have already fought against Dark Emperor a couple of time. The one present on the field is the same except color difference. Make you sure you have a few allies at the end so you can defeat the king.