change it with "a ball of water"
Nah, our GM usually let us to use the Throwing skill on physical objects only. Because one of them actually tried to throw someone's "Ball of Light" spell. Fun times.
I was actually thinking if it would work on D&D and, surprise, it does: a Ranger specialized on Throwing weapons and specced on the usual tennis skills. And the abilities ARE what sometimes Rangers are able to do.
if you want to fanfic all the ridiculousness, sure, you do you
As a veteran TTRPG player let me tell you: even the most serious, grimdark and "adult" setting can and will go into silly territory if you want to. Sometimes, by taking it so seriously it becomes cringe AF (as grimdark tends to be).