If your troop with Necromancy die, you will not obtain the bonus… whereas the counter said the contrary…
For example (my soul bonus is x3.5), when I use one time Valkyrie with one Necromancy troop alive, I have 30/60 souls and I obtained 105 souls.
But if the troop with Necro die, I still have 30/60 but only 70 souls…