Superlative form: most flawy; having the most flaws or defects.
From 'flawy' plus the superlative suffix '-est' (from Old English '-est'). Superlative forms mark the highest degree of a quality among three or more items.
Nobody actually says 'flawiest'—we'd say 'most flawed'—which shows that English superlatives on longer adjectives sound forced and unnatural to our ears!
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