How can I make a Boss that you can interact with, then fight him, then has one last dialog before he beams away?

You would have to have an npc contact for the boss with the objective "dialog with npc contact." This contact would disappear after the objective of speaking with them was completed. A boss Squad would replace them with the new objective "kill enemies" and then a second NPC contact made to look just like the first one would become visible for the final objective "dialog with npc contact." As far as I can tell, there is no way to have a singular boss as an enemy to kill, only the "Captain" groups.

Making NPC contacts disappear is not a feature of the Foundry and cannot be faked very easily

I was trying to mimic like the Romulan Female commander in the episode with the Borg assimilated War Bird.

There's a trick I use to mimic this. Place your boss where you want him to appear. Place an invisible wall between the boss and where the player will be when he enters the room. Place a reach marker in front of the invisible wall. Have a map dialog set to become visible when the player reaches the marker. The map dialog should contain what the boss will say prior to the fight. Set the invisible wall to disappear on component complete of the map dialog.


And Vola, the reach marker triggers the boss's speech and the invisible wall prevents him from initiating combat until he's done talking.

That's if you want to talk to him then fight. If you want the boss to talk and then disappear, there is a workaround.

First, within whatever map you're using, put in a raised platform and put the boss on top of it. Make sure you place walls or objects around the sides of that platform so that people can't see under it, and a ramp so the player can walk up and talk to the boss.

Then, after an initial conversation, have the player leave the room for some reason. For example, after talking to the boss he tells you to do something with a computer in the next room. You leave the boss, maybe spawning some npc "guards" there to keep an eye on him. You go to the next room and activate a console. Now, the raised platform the boss is standing on, set that to go from visible to invisible on component complete and select that console in the next room. This will drop the floor out from under the boss and he will fall into the space under it.

Next you use a map dialogue to have one of the guards call you saying "Sir, he beamed away!" Create a new platform in exactly the same coordinates as the old one and set it to go from invisible to visible on dialogue prompt reached, and set it to that dialogue with the guard. You have the player run back and look at the empty space where the boss used to be. The boss is actually in the space under the new platform, but the player has no way of knowing that.

Also.... you can use the Boss's image in a dialogue window whether or not there's an interactable NPC that looks like the boss.