So, I was playing against the AI for some challenges. Every time an enemy champion actively moved, on their turn, adjacent to the Orb of Protection (mine), several things happened: 1] The enemy champion became untargetable with activated abilities and spells (auras, AOE, Manic, etc. could still target them and damage/affect them). 2] The enemy champion's sprite would either disappear, or appear "on top of" the Orb of Protection, until they moved away or attacked.