Wait, you're asking what level in Everything2 we can learn fireball? You could have checked the XP system, but it's level 15. Sorry about those writeups above, they really just love their video games.
Take note that if you attempt to /fireball while underleveled, it is guaranteed to fail, and whoever is active now will see it (even if you don't see anyone in the "Other Users" nodelet, it's still not safe!). Do you want to be shamed and mocked by your fellow noders? No? Then stop reading this and grind yourself to that level. With quality, of course.