After a cut-scene, Senua will leave the voices behind her. Go forward towards the mirror. Get to the other side.
After a cut-scene, you will find yourself in the Heli realm. You will see the Goddess herself from afar - run towards her.
After reaching the platform, a fight with a lot of enemies will begin. They're mostly shieldsmen, regular warriors and axemen. Use focus and charge often. Notice that you're way more powerful.
After the fight, get to the destroyed bridge and the path to Heli will open. Another cut-scene will happen. After that, a shadow of each boss you destroyed will appear. You have to defeat them again - they're not as powerful as they were, but the fight isn't going to be easy. Your bet is patience - don't act stupid, try to deal safe damage.
There's just too many of them...
After the fight, approach the fragments of the bridge - get through. You will reach Heli herself... a sea of enemies will be conjured. Fight as long as you can, give it your best shot, but you will never win... When our protagonist finally falls, the final cut-scene will commence.
Congratulations! You have managed to overcome the madness and reach the, unfortunately bitter, end of the journey. Thanks.