This stock motion graphics video shows a time travel portal with electrical charges and papers and debris flying around it.

This effect has Alpha Channel but the sphere/portal in the middle is not transparent so you will need to use some blending modes. Check out the preview video to see an example. In my tests I realized that Lighten, Add, Screen and Multiply modes seem to work best.

So place a naked man behind the portal and you are ready to start your robot mayhem!

24 fps - Alpha Channel - 1920x1080