Adding onto what was said above:
The Buster Sword R5 (unlike the Takeover’s Buster Sword R2R5) is a Universal Mythic Melee Cosmetic that has no gameplay abilities and can be equipped in place of your heirloom or fists. The sword will not be coming to the Mythic Shop after the event ends, so unlock it while you can!
From: [EA] APEX LEGENDS™ & FINAL FANTASY™ VII REBIRTH EVENT
IMO it does suck, does create a lot of FOMO and well, just not all too great.
The Buster Sword isn't all that special either, as it doesn't have a lot of animations as far I'm aware, plus it takes up a large portion of the screen.
So I don't think you'd be missing out on much.
