na-adjective
what sort of; what kind of; in what way
A somewhat formal or literary adjectival noun used to ask about the nature, type, or manner of something. Often interchangeable with どのような or どんな, but いかよう carries a more classical or written tone.
いかようなご用件でしょうか。
What sort of business do you have?
いかようにも解釈できる表現だ。
It's an expression that can be interpreted in any way.
Derived from the classical Japanese interrogative いか (how) + よう (form, appearance). The kanji 如何 are ateji for the reading いか.