Delete yourself.
She can't oneshot anyone if she only has 2 damage items, she'll barely be dealing any damage if that's the case. Like, say those 2 items of damage are Ravenous Hydra and Black Cleaver. Including runes and her Doran's Blade, that gives about 130 bonus AD. This would give her about 8% max health true damage per vital struck, and her Q would do 255ish damage. So if this Fiora, at max level, hit your Vital, ulted you, then Q'd you twice and hit you with both hits of Bladework, hitting every single Vital on you (which, by the way, would take at least 5 seconds, which is hardly a oneshot), she would be dealing all of 1500 damage + 40% of your max health. That's not even enough damage to kill most non-squishies, and again, it was over 5 seconds, meaning her DPS is a pathetic 300 +8% max health.
If you want actual examples of characters who can oneshot with only 2 damage items, see Xin, Jax, Vi, and Hecarim.