Pepper's Flame
Doodled on:

...hehe, I'm just messing with you.
back when i was thinking about litwick's flame, the headcanon i had was that the flame is maintained by litwick's own soul, thus necessitate the consuming of others' souls for upkeep. Thus, this doodle comic was born.
nowadays, this headcanon has changed, such that the flame is merely an indicator of litwick's wellbeing (similar to charmander). Its soul consuming ability doesn't really depend on the flame, but an ability that all ghost-types can possess. However, litwick can draw a soul flame from it, which will have soul-consuming properties.
as for the soul part, the headcanon is that Litwicks (and ghost-types by extensions) can feed off souls, but most decided that physical food is tastier and more filling.