Another possible reason Snape killed DD

[Tonks]

No: HPFGUIDX 135252

Here is another rather far out idea.  What if DD is immortal, like 
Fawkes? He is not really human, he is an immortal being. 
Look at the clues:  Fawkes has only been DD's.  DD patronus is a 
phoenix.  And as he is nearing death, his arm appears
 what
 
BURNED.  Is it his Burning Time??  When Harry looks into the flames 
he sees a spiritual phoenix rising from the ashes.

Maybe it was time for DD to move on and along with all of the other 
reasons why Snape had to AK DD, this was one of them.

Symbolically this has many meanings. First one could see DD as a 
Christ figure. Also he might be a symbol from another religion
as well, perhaps Buddhism. My thinking here is that he has all of 
those names, so maybe he reincarnates over and over just like Fawkes 
and each time gets another name added. (He started his "burning time"
with his arm. And Snape helps him along at the end.) Then I also
wonder if it is like with the Dalai Lama. Was Albus the last one and
now Harry is the next (the chosen one)? Of course, the Chosen One
refers to Jesus in the Christian religion, the Messiah in the Jewish.

Tonks_op