How can I go about attaching a sprite (in my case a muzzle flash) to my weapon's muzzle bone when firing?
I've tried using the Sprite Attacher script but it only seems to let me override slots which doesn't really help my case.
The reason for having the muzzle flash separate from the weapon file is because multiple if not most of my weapons, will use the same muzzle flash.
So in my case:
The bone in question is fire-primary, how can I attach and detach my muzzle flash sprite at runtime.
Attaching Sprite to bone at runtime
RogueWars I think what you are looking for is the BoneFollower component, which allows you to have any GameObject follow a specific bone of your skeleton. See the spine-unity runtime documentation for more information: https://esotericsoftware.com/spine-unity#BoneFollower
Thank you once again, I was under the impression that it only applied to SkeletonAnimations.
RogueWars Ah, the BoneFollower component references a bone of a SkeletonAnimation component, but you can use BoneFollowerGraphic for the SkeletonGraphic component:
https://esotericsoftware.com/spine-unity#BoneFollowerGraphic
@RogueWars Your gun pixel art looks very cool! 
For the future: mentioning up front which Spine component and which exact version of the spine-unity runtime you're using might save some unnecessary writing back and forth to clarify your setup and get the answer you need.