Err, the explosion thing I forget, but the typical ways of making an explosion are:
1. create and kill a hawk with triggers
2. same thing but with petard
3. Same thing but with cannon ball. This gives a white cloud, but you need to unlock the cannon ball in GeniEd2. Search the utilities section of the blacksmith and download it. Find the bombard cannon, check what it's projectile ID is, find that projectile, unlock it by unchecking the "hide from editor button" and you can know place it or create it with triggers. I bet this is what he used, but I haven't played this scn in a while.
the two holes in the island are actually shadows of scorpion shots. You will notice that there are lanterns with scorpion bolts around them in a ring. Unlock the scorpion shots the same way you did the cannon ball.
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