奇异 is a stative verb (s.v.) that covers two related but distinct senses: describing something as strikingly unusual or bizarre (like a strange sight or phenomenon — more literary than 奇怪), and describing a person's feeling of astonishment or amazement (often in phrases like 感到奇异 or 神色奇异). It can also carry a slightly positive 'extraordinary' or 'marvelous' flavor in contexts like 奇异的景象. The word is less common in everyday speech than 奇怪 or 惊讶; it appears more in written or formal narrative.