There isn't a single, universally accepted term for a character whose traits are complex and cannot be easily summarized. However, here are some terms you could use, depending on the specific aspect of their complexity you want to emphasize:

Focusing on their depth:

* Nuanced: This implies the character has subtle and intricate motivations and actions.

* Multifaceted: This highlights the character possessing a variety of traits and perspectives.

* Complex: This is a general term that simply suggests the character is not easily understood.

* Multidimensional: Similar to multifaceted, but emphasizing their depth rather than just their number of traits.

* Well-rounded: This emphasizes the character having a complete and realistic set of traits, both positive and negative.

Focusing on their unpredictability:

* Unpredictable: This term emphasizes the character's tendency to act in ways that are not easily anticipated.

* Ambiguous: This suggests the character's motivations and intentions are unclear.

* Mysterious: This implies the character has secrets or hidden aspects that make them difficult to understand.

Focusing on their dynamism:

* Dynamic: This emphasizes the character's growth and change throughout the story.

* Evolving: This term highlights the character's transformation and development over time.

* Developing: This suggests the character is still learning and changing, making them unpredictable.

Ultimately, the best term to use will depend on the specific qualities of the character you're trying to describe.