Of course, consuming your soul force was something no one would do as it would not only be extremely painful, but it would also weaken you tremendously and cripple your cultivation.
Cain assumed that the mummified Legend should have used a way to trap the souls and used them as a catalyst for the Legendary Innate Ability so he would not have to use his own soul force.
'I wonder if I could use my gray flames. They consume souls, so it should be useful.' A wistful light appeared in Cain's eyes as he concentrated on his energy pool.
The Legendary Innate Ability of the mummified spellcaster was unlike those of Lamerto or the demonic dragonborn. It did not have a massive effect or range, so it could be used without anyone noticing, giving Cain the perfect chance to prove the effect summoning those powers would have.
