I must point out that you are dealing with powerful symbols when dealing with DC.
The way you treat them determines your timeless status in an field where time is actually absent.
So your possible willful attack against a DC, and the eating of his soul might be harmless in a real waking life, but it might dangerous-disastrous in LD.
In true LD there is an eternal timeless NOW !
Your attack and your DC soul devouring, is not enriching your existence, but on the contrary it is Identifying you emotionally with the negative elemental world beyond the time needed for a possible self healing.
As I strongly believe that Ld and Death are of the same fiber (and perhaps for the same regenerative reason) it is always best to fight motivated from love.
Even if you are ever obliged to kill, killing a DC should be your last and absolutely unavoidable option, and always in defense …
May the light be with you,