...Neither of the two NTR endings would really fit as canonical endings — unless N_taii intends for HC3 to start interfering with future installments of the series.
If you remember, the Duke mentions that by completing the ritual they talked about, they could use the Peacekeepers to enslave nations. In my opinion, those two NTR endings would leave the story at a point that’s way too invasive for future entries.
the NTR endings might be workable as the true ending if HC4 is about the aftermath of NosRa attacking other lands. maybe we will see was
Sony Toshiba Hitachi Casio from HC1 making a cameo as one of the characters getting in the way of a fully operational
death star tower.
but yeah, an NTR ending would probably be too invasive. and every HC chapter so far has been independent of each other.
The streets are begging for a true ending...
It would probably be bittersweet though.
in HC1, the true ending has
Casio's existence was basically erased from everybody's minds and he becomes a wandering adventurer on a mission from (cat) god.
in HC2, the true ending has
Noah returning to an abandoned village with only his mother left and both of them waiting for a comatose woman to wake up.
in a hypothetical HC3 true ending, just imagine what
Jared Leto will undergo.
at the very least, it's probably a good guess that whichever of the 4 endings HC3 is the most bittersweet, then that's most likely the "true" ending. or whichever is the longest ending could also be the "true" ending.