My Talent Is F-Rank, So I'm a Loser. But What If I Have Two?

Warning! This story contains a serious twist. In the apocalypse-era talent assessment, everyone else gets an S, A, B, or C, but I get a double F. Instructor: Give up. If you run into a ferocious beast, you won’t even be able to escape. Chen Ye: Got it. I’ll get dinner ready. My double F doesn’t mean I’m weak. It means I’m compatible with everything. Ferocious beast cores are snacks, and demon essences are supplements. While all the other geniuses are fighting for their lives, I’ve already eaten my fill and come out with a blade to clear the field.