I presume you mean you accidentally dragged an icon off the hotbars. Happens to everyone, in many games and is not Larian's fault.
Is the said Repelling Blast listed on the "skills" page. Most features are listed there, but there are bugged exceptions.
How : press the default key to open the page that shows spells, actions, etc. You can find the said keybind via Settings ...
Tip : once satisfied, there is a lock icon on the right-hand side of the hotbar which serves to avoid dragging icons of the hotbar by mistake.
Last edited by Baraz; 11/10/20 01:28 PM.