[@mattmanganon]
Unfortunately I'm going to have to deny you again.

Any sword made to be unwieldy is not a proper weapon and thus should not be used on the battlefield. Biting Blades included. Especially Eldar weapons. Any two-handed swordsman would know how to make that two handed sword into a whirlwind of death, and any swordsman would be wise to practice in some sort of wrestling. Any Knight who does not practice wrestling wrestling is a failure of a swordsman. Assuming your character is not a failure of a swordsman, taking out the common Heretic [i]would [/i]be like swatting a fly, since your Biting Blade would be like a whirlwind of chainsaw death. Actually, taking out five common Heretics would be like trimming your front lawn with a lawn mower, if they are all armed with small knives and swords and are as suicidal as Cultists usually are. Here is a video of a two-handed sword is like.
https://youtu.be/TZtZV3Dy3i8?t=107

I have also never heard of any sort of Eldar life debts, nor have I heard about them gifting weapons to any humans. To make sure, I asked a couple of people. They all have never heard of an Eldar life debt, and neither have they heard about the gifting weapons deal. 

I'm okay with with the Biomancy and the Plasma Pistol, or a Melta Pistol equivalent. I am also alright with the Admech background and the acceptance of using Xenotech, given your reason.
What I am not okay with is the Eldar Biting Blade and Fusion Pistol. Particularly with the Biting Blade. Psykers typically carry some sort of staff to amplify their abilities, I would accept a spear or pole arm, as it's basically a staff with a fancy tip. But with the reason I stated earlier, having never heard of any life debt or weapon gifting, I'm having a hard time accepting your load out. Then there's the balance issue. In a one on one fight, with only the swords, a skilled user of the Biting Blade alone would make my own character be extremely careful. A skilled user of the Biting Blade with Biomancy abilities would make him just give up and run, that's how powerful your combination of Biomancy and Biting Blade is. 

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Posting tomorrow night, there will be grills.
Both OOC and IC. IC grills will be harsher though.