Overall, a 3S Rating was not Lu Ran's limit; instead, the highest rating achievable in the Breakthrough Secret Realm was only 3S.
Having hunted a Level 100 Middle Legend, it even dropped an "Legendary Resource" along with numerous "Epic Resources." If the rewards from Infinite City capped at epic-level resources, that would be rather stingy.
Therefore, Lu Ran felt that under the unimpressive traits of "Shiva Arms and Legs Attribute" and "Hunting Instinct Beast Training Technique," this legendary exotic beast egg should grant him a spectacular prize to match his hunting results.
Even if the reward value surpasses "Zhu Yan" itself, bursting out a stronger exotic beast cub would still be considered reasonable.