"Oh, don't worry, it's just a little tranquilizer solution, nothing lethal. It'll wear off in a few hours, you should be just fine afterw-...oh, you passed out," I remarked, before getting back up onto my feet and taking out a Healing Potion from my Item Box with a weary sigh.
Earlier, when I said that I guess I'll just have to lose, what I meant was that I'll make him think that I lost, which would inadvertently make him let his guard down. And it worked, he dropped his guard and gave me an opening.
His large scale attack with all those vines definitely helped me pull that off, I had to think pretty quickly, it was quite the high intensity situation. One misstep and it would've been curtains for me.
I decided to put all my focus solely into evasion and run out the clock on his Mystic Transcension, since I didn't have much else of a choice. I got lucky that it happened a lot sooner than I was prepared for.