Chain Lightning (data editor) + Chain Healing
A chain lightning ability done with only the data editor.
It bounces from one unit to another 15 times, never hitting the same unit twice, doing decreasing damages, and has a jumping beam actor.
New version for retail SC2 + mod version.
There's also a 5 jumps Healing Beam which us the medivac's beam.
See Help page here to change number of bounces.