Basically, at the next time you do hit with a melee weapon attack at the time of this 5e spell’s duration and also your attack deals an extra 1d6 psychic damage. In an addition, if the target was a creature, then it should make a wisdom saving throw or else it should be frightened of you until end of the spell.
Have you read maddening darkness spell 5e
So, like an action, the creature can able to make a wisdom check against your spell save DC for steeling its resolve and also end this spell.
Attributes Of Wrathful Smite 5E Spell
|Casting Time||1 bonus action|
|Duration||Concentration, up to 1 minute|