The giant flame lizard, the Elder Salamander Prince Zenon, was a spirit on par with Sinea, as evidenced by his level and naming convention. As spirits, they were the peak of their respective elements and were incredibly rare.

[Since spirits don't naturally grow on their own, contractors are indispensable. Stimuli, experiences, will… All these factors have an effect on a spirit's development.]

"Then what about you, Sinea?" asked Lee Shin-Woo.

[Me? Well... You and I are pretty much already contracted, Paul Zero.]

Sinea blushed and seemed embarrassed. That was enough for him to figure out what was going on. When he gave her the spirit stone in the past, she had awakened as a Dryad Princess; a contract of sorts must have formed between them.

[...It seems like you met a good contractor. How enviable.]

Zenon breathed out a tiny bit of flame and gazed at Sinea. It didn't seem like he was being sarcastic; he appeared genuinely jealous.

The reason was easily explainable. Sinea had just said it. A contractor was essential for a spirit to reach level 7. Zenon must've had a contractor in the past...