You create a minor manifestation of fel or demonic magic within range.   Choose an effect that fits within a 5-foot cube, such as:   Flickering green flame. Glowing demonic eyes. A horned shadow A whispering infernal voice. The smell of brimstone or ash. A glowing rune.   The sound of chains, claws, breathing, or distant laughter.   The effect:   Cannot deal damage. Cannot create bright light. Cannot physically interact with creatures or objects. Cannot clearly communicate a full spoken message. A creature examining the illusion may use its action to make an Intelligence (Investigation) check against your Warlock spell save DC. On a success, it recognizes the effect as an illusion.   Fel Flicker ends if you dismiss it or cast it again. A small rune glowing on a nearby surface A faint supernatural sound, such as chains, claws, breathing, or distant laughter   The illusion must fit within a 5-foot cube and cannot deal damage, create bright light, physically interact with creatures or objects, or clearly speak a full message.   A creature can use its action to inspect the illusion. On a successful Intelligence (Investigation) check against your Warlock spell save DC, the creature realizes the illusion is false.   The illusion ends early if you dismiss it as a free action or cast this spell again.