Exemple: A Pokemon comes with Intimidate, and my Pokemon has Defiant and White Herb. Does the White Herb nullify the Intimidate and then Defiant puts your Pokemon at +2 Attack? On Pokemon Champions.
Defiant and Competitive activate before the White Herb. If you have a Pokemon with Defiant and it gets hit by Intimidate while holding a White Herb, you will end the interaction with +1 Attack and your White Herb remains unconsumed.
White Herb (Bulbapedia)