The origins of Demon Cyborg and his avenging vocation?

So in the first episodes, we get treated to this long and comically over-dramatic introduction monologue from Genos (Dem0n Cyborg) in which he speaks about how his village was destroyed by another evil cyborg.

In the following volumes with the House of Evolution he seems very focused on revenge and getting more information at this, although unsuccessfully (from example from the cyborg gorilla).

Yet, later he (or ONE/Murata) seems to forget all about that. Even as dr. Bofoi was said to be the next big threat

[spo1ler] I have read up until the defeat of Cosmic Garou in the manga and nothing forthcoming apparently.

So is this storyline completely dropped and forgotten, or does it ever appear again? Would have been interesting. Otherwise it seems the only thing Genos does is fight, get destroyed (every time obviously), and get reconstructed stronger (only to be destroyed again all the same in the very next big fight).