A very similar situation happened in an old campaign of mine where the player had some fair warning about consequences but went and did a thing that blew up a fucking moon of the setting.
The environmental consequences alone defined the next few generations of the setting. I just rolled with it and after a while I went from
to 
you can't just introduce a gun in the first act and not expect the players to shoot it in random directions
Tbh is the dm that had the dumb idea of putting that object there... What good would it do storywise?
It's a powerful weapon to use in a safe situation, but you also must keep it safe until that moment. Adds difficulty temporarily and then it's an absolutely astonishing grenade. Throw it at a dragon with magic and watch it burn itself to death. Or be careful to not use any small magic (tough for puzzles and stuff) in order to have a super dangerous weapon.
Also you can just make up something that nullifies it that some enemy brings and it never works again after that, like the main enemy of the dungeon it was found in or so who had hoped to act as a trap to kill you with it (just like these characters probably did)
The real question is why Azuth has big wooden sticks for fingers.
Same reason so many legendary sorcerers have giant gems for eyes or hearts.
Wizard: “I say we nuke the whole site from doorway. …it’s the only way to be sure.”
Complete answer: https://lemmy.world/comment/3129632
TL;DR https://lemm.ee/comment/3180797
