昆 (kūn) covers 'Qu-' and
恩 (ēn) approximates the '-inn' nasal — note that the apostrophe in Pinyin (Kūn'ēn) marks the syllable boundary so it isn't read as 'kūnēn' run together. The same
恩 shows up in countless name endings (
肯恩 Ken,
卡恩 Kahn,
史蒂芬·
昆恩 Stephen Quinn).