The glowing eam of yellow light marking that guy as target..
Savage2 has green light piller pings for making "move here" on the ground. If you can't see them it makes an arrow on the edge of your screen. Then you have "attack this unit" pings for clicking on someone that has a piller of light shining on them.
Demigod NEEDS them. It wouldn't be hard at all to implement. It's justa particle effect and sound effect that only allies can view.. the arrow thing on edge of screen would be a bit more work, but still, basically simple stuff that'll greatly improve the ui.