Yeah, I'm willing to bet an eventual Relria fight will happen once she's absorbed x amount of lvs.
Also it'd be cool if there was a tradeoff for soul draining. Like once you absorb a soul, you trade off the power boost for your kink. So Sophia would no longer have her kink, she's just really strong. Maybe with the added wrinkle that after enough time since the last soul drain (talking about a few centuries at least) the kink starts coming back, but never as strong as it was to start with.
Also it'd be cool if there was a tradeoff for soul draining. Like once you absorb a soul, you trade off the power boost for your kink. So Sophia would no longer have her kink, she's just really strong. Maybe with the added wrinkle that after enough time since the last soul drain (talking about a few centuries at least) the kink starts coming back, but never as strong as it was to start with.