The eighth trial was cleared by only nine teams so far. It's because these nine teams had geniuses that killed either only a few people or didn't kill anyone at all. They became stronger solely with herbs, elixirs, and other goodies.
For these people, the eighth trial was the easiest. But in a way, they just cheated their way out. Of course, Varian team's victory also cheated by taking help from the turtles.
But if they really did try to clear the trial in an upright manner, the three of them needed to face by themselves the army and powerhouses that killed ten turtles, each of which was a powerful Sovereign!
There's just no way they could've won. The probability of success, no, the possibility was plain zero.
In other words, the trial was meant to be unbeatable. And the only way to beat it was to cheat.
"Finally," Varian slowly landed on the ground and looked around.