フッ
Meanings
Interjection
1. hah (derisively); pooh
Adverb taking と
2. pfft (of something disappearing); poof (Onomatopoeia)
3. huff; puff (Onomatopoeia)
Examples1
ふっ、 禁断 の 魔術 とやら は、 俺 には 通用 しない ぜ!
Hah, your 'forbidden magics' aren't going to work with me!