Most of the time, a relationship with a narcissist has three phases.
Initial phase: Lovebombing and Futurfaking.
Second phase: Verbal devaluation, gaslighting, financial exploitation.
Last phase: Contact broken, which is sporadically resumed (on/off relationship).
The codependent partner is usually already in love and finds it very difficult to end the relationship.
Relationship patterns learned in childhood usually play a role here. It is very difficult or impossible for the co-dependent partner to become aware of dependencies and their causes. Therefore, such relationships are usually maintained over a longer period of time, years sometimes, even decades, mostly women are in the codependent role.
If such a relationship can be ended at some point, the codependent partner usually finds themselves in a similar situation again.