Let’s test on your second string:
Another possibility: (shift by 13): d → q a → n n → a l → y w → j d → q → "qnayjq" — not matching a known word. Blue Is The Warmest Color danlwd fylm ba zyrnwys chsbydh
Given the title, maybe the second part is the ? Let’s try: "Blue Is The Warmest Color" in ROT13: Oyhr Vf Gur Jnezrfg Pbybe — not your string. Let’s test on your second string: Another possibility:
That gives "wzmodw" — not obviously right. Blue Is The Warmest Color danlwd fylm ba zyrnwys chsbydh