Intense describers: Accursed! Hideous! Disgust!
The monster uses the most intense adjectives possible.
Type any adjectives you currently use into Thesaurus.com and see if you can find more intense alternatives.
Be selective! This isn't about stuffing random words everywhere; it's about making deliberate choices for effect.
Using a title instead of a name: Accursed creator!
Notice how the monster doesn't say, "Accursed Frankenstein!" Instead he identifies the doctor by a role, which elevates him into more of an abstract power.
If you named someone, can you refer to them by a title or role instead?
Word order in a noun group: A monster so hideous!
In everyday speech we'd say, "Why did you create such a hideous monster?" But Shelley flips the order so that the emphasis lands on her intense describer, 'hideous'.
Is there a noun at the heart of your complaint? Is there an adjective that describes it? Can you shift the adjective after the noun?
Intensifying: So hideous that even you...
The monster intensifies the complaint by saying, "even you, the one person who should love me, turns away".
Is there a way you can use this phrase to jab your finger at the person you're accusing?
Compression: That even you turned from me
In contemporary speech we might say, "turned away from"—but 'away' is redundant, and cutting it compresses the speech and increases intensity.
Are there any words you can cut? Any ways you can make your phrasing more compact?