I would really love to see some iteration of Alarak's Lightning Surge in League at some point

Excerpt from the above link:

Lightning Surge Deal X damage to an enemy and an additional 100% damage to enemies between Alarak and the target. Restore Y health for each Hero hit.

I love this ability in Alarak's kit because it requires you to take a different approach to targeting. Rather than targeting an enemy Hero directly, you want to target something so that said enemy Hero is between you and your selected target. This way, they take the most damage possible.

The following should provide a better demonstration: https://youtu.be/hep-bsMW1rU?t=98

League does not have an ability that's even close to this (unless I'm mistaken), and it would be a very unique ability with a high skillcap. I hope to see it in some shape or form in the future.