The green tent (located above the elves) opens a passage to the last enemy hero (a castle in the dungeon); the tent is guarded by emerald dragons. A one-way portal leads to them (to the island). You cannot leave or return from the island, and you have to defeat the last hero. What should you do? The dragons are strong. Personally, I defeated them with the help of allied elves and a leveled-up elven hero + the castle's population. But, the scenario also suggests sacrificing the liberated elves. And then, the second strong hero won't appear. What should you do?