如何(いか)なるWhat kind of, No matter what kind of, No … (with a negative verb), Any... (with a negative verb)

如何(いか)なる is a combination of 如何(いか), and なる. なる being derived from the classical auxiliary verb なり 'to be'. 如何(いか) is never used as a word by itself, and will always be attached to something else when it has the reading of いか. However, its meaning is the same as the modern どう 'how'. Because of this, いかなる is interchangeable with どんな 'what kind of', with the exception that it is primarily used only in books and formal writing.

いかなる is classified as being attributive, meaning that it will appear directly before a noun, or modify a noun somewhere within the same clause.

Just like どんな, when に is added to いかなる, a negative statement will usually follow. This translates as 'no matter how much (A)', or 'no matter what kind of (A)'. However, に will not directly follow いかなる like it does with どんな. Instead, it will appear later in the sentence before the verb.

Occasionally, いかな may also be used, but this is far less common.

Fun Fact

Both な and なる are derived from the classical auxiliary verb なり. Structures that stem from なり can be seen in many modern parts of the Japanese language. This also includes なら, the hypothetical form of だ, which shares the same meaning of 'to be' as なり. While な is the form that appears with most adjectival nouns, なる is still sometimes used in place of な when the speaker wants to be poetic, or give a sense of archaism.