Combat Awareness

Combat Awareness states

"This unit only takes damage from spells and abilities if they specifically target a champion. This does not include terrain effects, conditions, or equipment on this champion."

Thus it prevents damage area of effect spells and abilities, but does not prevent damage from attacks and abilities that directly target it.

It also seems to generally work on "auto target" effects -- that is when a champion is chosen by the ability rather than the player (such as if a spell like Retribution affects the "closest champion") or if a relic affects all or some champions in a certain range (such as Hive or Artillery Marker). However Combat Awareness does prevent Sonic Greeting.

Combat Awareness still has some consistency issues, however recoding it would take significant effort. Thus it may be reworked in the future. As a result, issues regarding Combat Awareness are given low priority over other bugs.