You considered you options and decided on going for the fourth option.
Mixing the mark into the rest of your soul shouldn't cause any issues that you wouldn't be able to handle.
You calmed yourself and slowly started kneading the black mark left by the marking stone into your bluish-white soul.
The mark dissolved, gradually turning into strings of black, that spread throughout the rest of your soul, before loosing shape their shape,
becoming patches of dark blue. You stirred them for a little longer, until your entire soul had become a slightly darker color.
You sighed, thinking that it had been easier than you'd expected, when you noticed that your soul was still getting darker.
Panic filled you, but nothing you tried was able to keep you soul from turning darker and darker, until it became a deep blue.
Everything started feeling heavy and your movements became clumsy. It felt as if your body didn't belong to you anymore.
You tried influencing your soul again, only to discover that you weren't able to use magic at the moment.
'W-what's going on?! This shouldn't be happening!' You looked around the room frantically, seaching for anything that might help.
You stumble and collapse onto the ground with your ass up, unable to get back up of your own volition.
'I have to concentrate, there has to be some way to fix this!'
Despite your best efforts, nothing seemed to work. 'I can't just- wait, what is that feeling?!'
You noticed a feeling that was suddenly starting to grow inside your body.