Hey again fdslk,
Sorry it took me a while to get back to you - been out of the office today.
First you’ll want to go and add a custom event notify (Right Click -> Add Notify -> New Notify) to the animations you are using, after you have added the event once it should just show up in the Right Click -> Add Notify context menu for other animations:
I’ve called it AnimEnd here, but you can call it whatever you like. Next, add an integer variable to your anim blueprint and set a random value to it on both initialise and on your custom event:
Finally hook it all up to a blend by int node in the anim graph:
That should get you the effect that you’re after.
If you need anything else let me know!