Essentially what you're saying is you found a private key collision on the Ethereum blockchain, and Ethereum would be broken as a result of it (since you are claiming you got access to someone else's ~$400k worth of ETH/ETC and could fuck them over if you are successful in liquidating it). If this was true, it would have a devastating effect on ETH and crypto as a whole. Pretty bold claim - would love to see the proof of it.
At last someone who understands my point. Yes I did! And not only a key collision, but I have an equal deterministic way of generating ethereum private keys deterministically from a bitcoin entropic constant and hit ETH keys with balances in them.
I can share proofs but posting people's addresses in public with bal in them most still in use is not a polite thing to do... but in private i def would! (screenshots, address, private keys) whichever requested. I don't know much about ETH like i stated before, but i know quite enough about bitcoin.
I dont understand it, why not just transfer first the eth you are saying here to a eth address that you fully control the pkeys and atleast show us proofs about what you are claiming, by that you will get serious help from knowledgeable people here in the forum