For those of you who are new to using Brawl Hacks, "Desyncing Wifi" simply means that something messes up
if the other person doesn't have the same exact files.
Things like doing different amounts of damage, an attack is faster or slower, or a completely different attack
will cause the other person's game to behave differently and just create a big mess.
While there are more examples, those are the most basic & common examples.

The other Final Smash works for sure because it's just a simple texture change, nothing that physically
effects gameplay.