There was another reason why I left Jade with Renna: we couldn't see each other.
Once we were inside, I couldn't concentrate on locating Renna since I had to concentrate on not making a sound. My stealth worked by deflecting light and blending my mana into the surrounding area, but if I walked noisily or kicked some stones, they'd be able to hear it.
It was fine if all they did was get alarmed--Jin would volunteer to check and pretend there was nothing. But if someone had a slippery hand and hurled their weapon at the source of the noise in reflect, there was nothing I could do but dodge or deflect--both were big movement that would break my stealth.
At any rate, I needed to take care of myself without caring for others. Especially because it was my first time in a ruin--and I had to work hard not to be distracted.