In the passage from the last chapter of Frankenstein, Shelley portrays the creature as more monstrous than Frankenstein. Shelley's choice of language in the passage emphasises the creature's rage, uncontrollable passion, and insatiable thirst for vengeance. The creature refers to Frankenstein as "generous and self-devoted" and expresses remorse for his actions, recognizing that his actions were monstrous and unjustified. On the other hand, Frankenstein's actions are not described in such extreme language, and the creature's actions are portrayed as the result of his own evil nature rather than being caused by Frankenstein.
One counterclaim could be that Frankenstein is also portrayed as monstrous in the passage, as the creature accuses him of daring to hope for happiness while causing him unspeakable torments. However, this can be seen as the creature's distorted perception of Frankenstein's actions, rather than a reflection of Frankenstein's true nature. Additionally, Frankenstein's actions are not described in the same extreme language as the creature's, such as "uncontrollable passion" and "insatiable thirst for vengeance".
In conclusion, Shelley's choice of language in the passage portrays the creature as more monstrous than Frankenstein by emphasizing the creature's extreme emotions and actions. While Frankenstein is also criticized by the creature, it is not in the same intense language as the creature's self-condemnation.