The in-game description says Paragon's Rebuke has a custom effect other than the icon, sound effect and ambient effects:
https://drive.google.com/file/d/1gsG...rjSfE-o2_/view

This is the current custom effect with and without the item:
https://drive.google.com/file/d/17ft...lbFoL4Rbq/view

After Repel was reworked into Heavenly Grace the custom effect was removed.

This is the custom effect before the rework:
https://gamepedia.cursecdn.com/dota2...uke_Valve.webm