Qin Wang was a fantastical gain. She was a Vagabond Cultivator that had been protected by the Heavenly Daos, having exceeded her master, becoming a high-level Ascended being despite possessing an enviable, desirable, and outrageously rare Yin Physique. When she encountered trouble, it led to her meeting an unrivaled Blessed of his generation with a profoundly mysterious past.
She was, by definition, the perfect instrument for an Interlinked Blessed's karmic fortune to propel them further and further. If she had met up with Su Yi, there was a strong chance that her Primal Overhaul Yin Energies would have advanced his cultivation by a stage, establishing firmer foundations than before.
It was commendable that Su Yi wasn't overly greedy for her back then, willing to wait. He kept the talisman that was bestowed to her by him, meant to be used to locate or alert him if she encountered dangers.