Idealization-Devaluation Cycle:

The idealization-devaluation cycle is an insidious narcissistic defense strategy for emotionally abusing and manipulating others (“victims”). The narcissist’s unpredictable, controlling behavior is intended to feed their narcissistic supply (continuous stream of attention, validation, praise). Also see Narcissistic Defenses. The idealization-devaluation cycle includes four distinctive phases: 

• Idealization (or love-bombing)begins the cycle by overwhelming the victim with excessive affection and attention, including: rapid intimacy (rushing the relationship, calling them soulmates, making grandiose gestures, like extravagant gifts or quick promises of a future), mirroring (studies victim’s mannerisms, passions, and vulnerabilities to be the perfect partner, making victim feel special), and isolation (pretending intense affection, subtly separating victim from friends and family).
• Devaluation: Once confident they’ve trapped the victim, the narcissist first subtly then overtly erodes their self-esteem (often their own façade slips, triggering their insecurities), including: increased criticism (replacing praise with insults, often criticizing the same qualities they once praised, or disparaging victim’s friends and family, discouraging spending time with them); emotional manipulation (using tactics like gaslighting, stonewalling, and triangulation to create confusion and keep victim off-balance, often projecting their own faults onto victim); and withholding affection or physical/emotional intimacy (leaving victim desperate to regain narcissist’s approval.) Once the narcissist has secured an emotional bond, they shift from seduction to fueling their narcissistic supply, changing their attitude and behaviors dramatically. The goal is to undermine the victim’s self-confidence. Whether aggressive or passive, their behaviors leave the victim feeling confused, off balance, and helpless. Victims often try harder to please the narcissist, desperate to regain what was initially so positive. But this satisfies their need for attention (narcissistic supply).
• Discard: In the most devastating phase, the narcissist abruptly and cruelly ends the relationship, without explanation or closure. Through rejection, they leave victim feeling abandoned and worthless (once narcissist no longer receives sufficient supply or has a new victim to target). They also use the tactic of blame-shifting (blaming victim for relationship’s failure, dismissing their feelings, denying any wrongdoing). When the victim no longer fulfills the narcissist’s needs, they’re discarded—often  occurs when the narcissist finds a new source of narcissistic supply, such as a new romantic partner or a different social group. Victims newly realize they’ve been in an abusive relationship as they note how they were emotional manipulated with a lack of empathy. This can increase their pain and confusion, as they deal with the sudden loss and the emotional whiplash from the cycle of abuse.
• Hoovering: When narcissistic supply is low, narcissist returns to “vacuum” the victim into the cycle, including: luring tactics (reuses idealization tactics, like charming apologies, promises of change, grand gestures); emotional appeals (guilt-trips or invents crises for sympathy and attention); and re-engagement (cycle of abuse restarts, with shorter, less intense idealization phase).