How to Complete Making Port
Although the quest objective is to defeat all foes, you actually only need to defeat Maquis the Ninja to make the quest end.
Harming the Opposite Sex is forbidden, so if you want to avoid breaking the law, don't let Adelle or any Vieras or Grias attack Maquis.
The other opponents are Alys the Ensorceled, who is a Viera Summoner; The Night Dancer, who is a Trickster (and is treated as male for the purpose of the Harming the Opposite Sex law); and Duke Snakeheart, an Arcanist. You can ignore all of these enemies since KOing Maquis ends the quest, or you can battle them also if you wish.