No dice. Please check the pics and video i have here so you can see what I have going on, I believe I have everything set up as you stated it . https://drive.google.com/drive/folders/1_qOA5zwblXDZCNxosQUdTQJ2nC9u6D_A?usp=sha...
If you haven't modified it, the Thorns VSBattleCore effect doesn't have a special battler motion associated with it, so it should use the guard motion. I tested myself in my test project (and found a bug associated with states, btw) and it does show the guard motion with the default battlers.
The picture of your golem battler is larger than a normal one, is it a dragonbones battler or something similar? The process for requesting a motion for one of those might use a different function than I use for a default battler. You might also need to add more wait time for the motion to have time to trigger? Does it work with any normal battlers for you?
Alright, so the issue is actually that there is no provision in the plugin for animated enemies to request a motion at all, so they never do. I believe this was a compatibility concern, as attempting to call a motion on an ordinary battler would cause a crash. I'll have to look into how to enable this for animated enemies, that might take me a bit, but I'm on it.