@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 would 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.
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.
Granted, most of what I am spouting is secondary canon, considering that it's in the games.
In Dawn of War II: Retribution, Adrastia can get an Eldar Harlequins blade which states in the description that it was gifted to the Imperium. It's description is something along the lines of:
"It's rare for the Eldar to allow humanity to handle their technology, but for unknown reasons, sometimes the doors of the Black Library open to allow some relics to be removed for Inquisition study. This is one such relic, gifted by the Harlequins that worship Cegorach, the Laughing God"
Essentially, they give humans technology under the permission that they use them on Slaanesh and its worshippers.
Also, according to a friend, Eldar Life Debts are an Oldhammer thing, this was from the days when
an Human/Eldar Hybrid could become the Ultramarines Chief Librarian. Also, these were the days when the Ultramarines were a successor chapter from the 3rd founding, that had been founded to replace Legion XIII, who had turned traitor with Horus.
Rogue Trader was fun, but I appreciate that it's not a thing anymore. I'll completely rework the character. Would I at least be allowed to be the Tank-Hunter of the group, though?