Epic hunt last night.
After a bad hunt of G Brachydios which carted me and my friend both at the same time, thus failing the quest, we decided to call it a day. But before that, since I unlocked Stygian Zinogre earlier that night, I asked my friend "Hey why don't we check it out? I'm curious about his moves."
So we jump in. Stupidly I brought Cold Drinks instead of Hot Drinks in the Tundra. What's more, I didn't bring any well-done steak and my BBQ spit. After getting exactly one steak from my friend, we proceed to the fight which was extremely dangerous. At one time my stamina bar was almost completely depleted, but fortunately I was wearing Barioth X armor so my evade rolls didn't take that much stamina. We was about to abandon the quest, but then something hit us--he didn't hit that hard. The hunt is doable.
20 minutes and two carting later, supplies arrived. We rushed back to the base to resupply.
Even with the new supplies, my stamina was soon back to its lowest. We played very safe, me using LS and my friend using DS. At about 35ish minutes, just as we despaired that the S.Zin looked very healthy despite our beatings, he began limping out. "Is this it?" so we moved to the next area, laid a shock trap, and captured him.
Then S.Zin Skymerald appeared in the quest reward.