I think I went too dark for the true ending, I might change it and re-write some lines Taramiel says to the MC My 'True end-game was always MC x Taramiel ending' but I rushed my writing to finish my main plot. So I'm going to re-write the true ending differently.
There are a couple of ways to represent the whole death thing without making it seen too harsh (like no blood/gore, something more akin of a ''clean death''), but i do believe the death ending could remain as an alternative if you find an appropriate way of portraying it. (would be an interesting alternative ending, that's for sure).
Although i agree with you that re-writing the ending would result in something more palatable.