Are there any downloadable spine projects for battle effects and animations (sword swipes, explosions, etc). I would like to try them out as a test and hopefully get some ideas on what I can make.
We don't have much of that sort of thing in our example projects. The powerup project has some stars, but it's quite basic.
You probably want to search for "VFX". Armanimation (warmanw here on the Spine forums) has a lot of great videos about that (as well as many other things!):