There is only occasionally a reason to use Forked Raiju over Fleeting Raiju in Final Fantasy XIV. The former is a gap-closer and thus moves your character slightly, while the latter does not. It’s not like using the former is usually worse, but there’s just no reason to. But I almost always use the former. Why? Because I think it looks cooler. That’s it. That’s the whole reason. It is a satisfying ability to hit.
Some abilities are just fun to hit. It’s not about how useful they are, and maybe you only get to hit the button that fires eye lasers once in a given encounter on any given night… but you love getting to do so, because it lets you fire freakin’ eye lasers. So what’s your favorite ability to use in an MMO? Maybe because it deals the most damage, maybe because it has the most satisfying effects, or maybe just because it feels really cool when it goes off?