Definition

Characterization
1. The creation or construction of a fictional character.
2. A description of the distinctive nature or features of someone or something:
^{Source: Oxford Language}

Classification
1. the action or process of classifying something according to shared qualities or characteristics:
2. The arrangement of animals and plants in taxonomic groups according to their observed similarities.
3. A category into which something is put:
^{Source: Oxford Language}

Ulquiorra Cifer, Bleach

Ryuk, Death Note